Electromagnetism
Electricity Magnetism
Electrostatics Electric charge Static electricity Coulomb's law Electric field Electric flux Gauss's law Electric potential energy Electric potential Electrostatic induction Electric dipole moment Polarization density
Magnetostatics Ampère's law Electric current Magnetic field Magnetization Magnetic flux Biot–Savart law Magnetic dipole moment Gauss's law for magnetism
Electrodynamics Lorentz force law emf Electromagnetic induction Faraday's law Lenz's law Displacement current Maxwell's equations EM field Electromagnetic radiation Maxwell tensor Poynting vector Liénard–Wiechert potential Jefimenko's equations Eddy current
Electrical Network Electrical conduction Electrical resistance Capacitance Inductance Impedance Resonant cavities Waveguides
Covariant formulation Electromagnetic tensor EM Stress-energy tensor Four-current Electromagnetic four-potential
Scientists Ampère Coulomb Faraday Gauss Heaviside Henry Hertz Lorentz Maxwell Tesla Volta Weber Ørsted
v t e

Magnetism is a property of materials that respond to an applied magnetic field. Permanent magnets have persistent magnetic fields caused by ferromagnetism. That is the strongest and most familiar type of magnetism. However, all materials are influenced varyingly by the presence of a magnetic field. Some are attracted to a magnetic field (paramagnetism); others are repulsed by a magnetic field (diamagnetism); others have a much more complex relationship with an applied magnetic field (spin glass behavior and antiferromagnetism). Substances that are negligibly affected by magnetic fields are known as non-magnetic substances. They include copper, aluminium, gases, and plastic. Pure oxygen exhibits magnetic properties when cooled to a liquid state.

The magnetic state (or phase) of a material depends on temperature (and other variables such as pressure and applied magnetic field) so that a material may exhibit more than one form of magnetism depending on its temperature, etc.

History[link]

Aristotle attributed the first of what could be called a scientific discussion on magnetism to Thales of Miletus, who lived from about 625 BC to about 545 BC.^[1] Around the same time, in ancient India, the Indian surgeon, Sushruta, was the first to make use of the magnet for surgical purposes.^[2]

In ancient China, the earliest literary reference to magnetism lies in a 4th century BC book called Book of the Devil Valley Master (鬼谷子): "The lodestone makes iron come or it attracts it."^[3] The earliest mention of the attraction of a needle appears in a work composed between AD 20 and 100 (Louen-heng): "A lodestone attracts a needle."^[4] The ancient Chinese scientist Shen Kuo (1031–1095) was the first person to write of the magnetic needle compass and that it improved the accuracy of navigation by employing the astronomical concept of true north (Dream Pool Essays, AD 1088), and by the 12th century the Chinese were known to use the lodestone compass for navigation. They sculpted a directional spoon from lodestone in such a way that the handle of the spoon always pointed south.

Alexander Neckham, by 1187, was the first in Europe to describe the compass and its use for navigation. In 1269, Peter Peregrinus de Maricourt wrote the Epistola de magnete, the first extant treatise describing the properties of magnets. In 1282, the properties of magnets and the dry compass were discussed by Al-Ashraf, a Yemeni physicist, astronomer, and geographer.^[5]

Michael Faraday, 1842

In 1600, William Gilbert published his De Magnete, Magneticisque Corporibus, et de Magno Magnete Tellure (On the Magnet and Magnetic Bodies, and on the Great Magnet the Earth). In this work he describes many of his experiments with his model earth called the terrella. From his experiments, he concluded that the Earth was itself magnetic and that this was the reason compasses pointed north (previously, some believed that it was the pole star (Polaris) or a large magnetic island on the north pole that attracted the compass).

An understanding of the relationship between electricity and magnetism began in 1819 with work by Hans Christian Oersted, a professor at the University of Copenhagen, who discovered more or less by accident that an electric current could influence a compass needle. This landmark experiment is known as Oersted's Experiment. Several other experiments followed, with André-Marie Ampère, who in 1820 discovered that the magnetic field circulating in a closed-path was related to the current flowing through the perimeter of the path; Carl Friedrich Gauss; Jean-Baptiste Biot and Félix Savart, both of which in 1820 came up with the Biot-Savart Law giving an equation for the magnetic field from a current-carrying wire; Michael Faraday, who in 1831 found that a time-varying magnetic flux through a loop of wire induced a voltage, and others finding further links between magnetism and electricity. James Clerk Maxwell synthesized and expanded these insights into Maxwell's equations, unifying electricity, magnetism, and optics into the field of electromagnetism. In 1905, Einstein used these laws in motivating his theory of special relativity,^[6] requiring that the laws held true in all inertial reference frames.

Electromagnetism has continued to develop into the 21st century, being incorporated into the more fundamental theories of gauge theory, quantum electrodynamics, electroweak theory, and finally the standard model.

Sources of magnetism[link]

Magnetism, at its root, arises from two sources:

1. Electric currents or more generally, moving electric charges create magnetic fields (see Maxwell's Equations).
2. Many particles have nonzero "intrinsic" (or "spin") magnetic moments. Just as each particle, by its nature, has a certain mass and charge, each has a certain magnetic moment, possibly zero.

It was found hundreds of years ago that certain materials have a tendency to orient in a particular direction. For example ancient people knew that "lodestones," when suspended from a string and allowed to freely rotate, come to rest horizontally in the North-South direction. Ancient Mariners used lodestones for navigational purposes.

In magnetic materials, sources of magnetization are the electrons' orbital angular motion around the nucleus, and the electrons' intrinsic magnetic moment (see electron magnetic dipole moment). The other sources of magnetism are the nuclear magnetic moments of the nuclei in the material which are typically thousands of times smaller than the electrons' magnetic moments, so they are negligible in the context of the magnetization of materials. Nuclear magnetic moments are important in other contexts, particularly in nuclear magnetic resonance (NMR) and magnetic resonance imaging (MRI).

Ordinarily, the enormous number of electrons in a material are arranged such that their magnetic moments (both orbital and intrinsic) cancel out. This is due, to some extent, to electrons combining into pairs with opposite intrinsic magnetic moments as a result of the Pauli exclusion principle (see electron configuration), or combining into filled subshells with zero net orbital motion. In both cases, the electron arrangement is so as to exactly cancel the magnetic moments from each electron. Moreover, even when the electron configuration is such that there are unpaired electrons and/or non-filled subshells, it is often the case that the various electrons in the solid will contribute magnetic moments that point in different, random directions, so that the material will not be magnetic.

However, sometimes — either spontaneously, or owing to an applied external magnetic field — each of the electron magnetic moments will be, on average, lined up. Then the material can produce a net total magnetic field, which can potentially be quite strong.

The magnetic behavior of a material depends on its structure, particularly its electron configuration, for the reasons mentioned above, and also on the temperature. At high temperatures, random thermal motion makes it more difficult for the electrons to maintain alignment.

Topics[link]

Hierarchy of types of magnetism.^[7]

Diamagnetism[link]

Diamagnetism appears in all materials, and is the tendency of a material to oppose an applied magnetic field, and therefore, to be repelled by a magnetic field. However, in a material with paramagnetic properties (that is, with a tendency to enhance an external magnetic field), the paramagnetic behavior dominates.^[8] Thus, despite its universal occurrence, diamagnetic behavior is observed only in a purely diamagnetic material. In a diamagnetic material, there are no unpaired electrons, so the intrinsic electron magnetic moments cannot produce any bulk effect. In these cases, the magnetization arises from the electrons' orbital motions, which can be understood classically as follows:

When a material is put in a magnetic field, the electrons circling the nucleus will experience, in addition to their Coulomb attraction to the nucleus, a Lorentz force from the magnetic field. Depending on which direction the electron is orbiting, this force may increase the centripetal force on the electrons, pulling them in towards the nucleus, or it may decrease the force, pulling them away from the nucleus. This effect systematically increases the orbital magnetic moments that were aligned opposite the field, and decreases the ones aligned parallel to the field (in accordance with Lenz's law). This results in a small bulk magnetic moment, with an opposite direction to the applied field.

Note that this description is meant only as an heuristic; a proper understanding requires a quantum-mechanical description.

Note that all materials undergo this orbital response. However, in paramagnetic and ferromagnetic substances, the diamagnetic effect is overwhelmed by the much stronger effects caused by the unpaired electrons.

Paramagnetism[link]

In a paramagnetic material there are unpaired electrons, i.e. atomic or molecular orbitals with exactly one electron in them. While paired electrons are required by the Pauli exclusion principle to have their intrinsic ('spin') magnetic moments pointing in opposite directions, causing their magnetic fields to cancel out, an unpaired electron is free to align its magnetic moment in any direction. When an external magnetic field is applied, these magnetic moments will tend to align themselves in the same direction as the applied field, thus reinforcing it.

Ferromagnetism[link]

Permanent magnet holding up some coins

A ferromagnet, like a paramagnetic substance, has unpaired electrons. However, in addition to the electrons' intrinsic magnetic moment's tendency to be parallel to an applied field, there is also in these materials a tendency for these magnetic moments to orient parallel to each other to maintain a lowered-energy state. Thus, even when the applied field is removed, the electrons in the material maintain a parallel orientation.

Every ferromagnetic substance has its own individual temperature, called the Curie temperature, or Curie point, above which it loses its ferromagnetic properties. This is because the thermal tendency to disorder overwhelms the energy-lowering due to ferromagnetic order.

Some well-known ferromagnetic materials that exhibit easily detectable magnetic properties (to form magnets) are nickel, iron, cobalt, gadolinium and their alloys.

Magnetic domains[link]

Magnetic domains in ferromagnetic material.

The magnetic moment of atoms in a ferromagnetic material cause them to behave something like tiny permanent magnets. They stick together and align themselves into small regions of more or less uniform alignment called magnetic domains or Weiss domains. Magnetic domains can be observed with a magnetic force microscope to reveal magnetic domain boundaries that resemble white lines in the sketch. There are many scientific experiments that can physically show magnetic fields.

Effect of a magnet on the domains.

When a domain contains too many molecules, it becomes unstable and divides into two domains aligned in opposite directions so that they stick together more stably as shown at the right.

When exposed to a magnetic field, the domain boundaries move so that the domains aligned with the magnetic field grow and dominate the structure as shown at the left. When the magnetizing field is removed, the domains may not return to an unmagnetized state. This results in the ferromagnetic material's being magnetized, forming a permanent magnet.

When magnetized strongly enough that the prevailing domain overruns all others to result in only one single domain, the material is magnetically saturated. When a magnetized ferromagnetic material is heated to the Curie point temperature, the molecules are agitated to the point that the magnetic domains lose the organization and the magnetic properties they cause cease. When the material is cooled, this domain alignment structure spontaneously returns, in a manner roughly analogous to how a liquid can freeze into a crystalline solid.

Antiferromagnetism[link]

Antiferromagnetic ordering

In an antiferromagnet, unlike a ferromagnet, there is a tendency for the intrinsic magnetic moments of neighboring valence electrons to point in opposite directions. When all atoms are arranged in a substance so that each neighbor is 'anti-aligned', the substance is antiferromagnetic. Antiferromagnets have a zero net magnetic moment, meaning no field is produced by them. Antiferromagnets are less common compared to the other types of behaviors, and are mostly observed at low temperatures. In varying temperatures, antiferromagnets can be seen to exhibit diamagnetic and ferrimagnetic properties.

In some materials, neighboring electrons want to point in opposite directions, but there is no geometrical arrangement in which each pair of neighbors is anti-aligned. This is called a spin glass, and is an example of geometrical frustration.

Ferrimagnetism[link]

Ferrimagnetic ordering

Like ferromagnetism, ferrimagnets retain their magnetization in the absence of a field. However, like antiferromagnets, neighboring pairs of electron spins like to point in opposite directions. These two properties are not contradictory, because in the optimal geometrical arrangement, there is more magnetic moment from the sublattice of electrons that point in one direction, than from the sublattice that points in the opposite direction.

Most ferrites are ferrimagnetic. The first discovered magnetic substance, magnetite, is a ferrite and was originally believed to be a ferromagnet; Louis Néel disproved this, however, after discovering ferrimagnetism.

Superparamagnetism[link]

When a ferromagnet or ferrimagnet is sufficiently small, it acts like a single magnetic spin that is subject to Brownian motion. Its response to a magnetic field is qualitatively similar to the response of a paramagnet, but much larger.

Electromagnet[link]

An electromagnet is a type of magnet whose magnetism is produced by the flow of electric current. The magnetic field disappears when the current ceases.

Electromagnets attracts paper clips when current is applied creating a magnetic field. The electromagnet loses them when current and magnetic field are removed.

Other types of magnetism[link]

• Molecular magnet
• Metamagnetism
• Molecule-based magnet
• Spin glass

Magnetism, electricity, and special relativity[link]

As a consequence of Einstein's theory of special relativity, electricity and magnetism are fundamentally interlinked. Both magnetism lacking electricity, and electricity without magnetism, are inconsistent with special relativity, due to such effects as length contraction, time dilation, and the fact that the magnetic force is velocity-dependent. However, when both electricity and magnetism are taken into account, the resulting theory (electromagnetism) is fully consistent with special relativity.^[6][9] In particular, a phenomenon that appears purely electric to one observer may be purely magnetic to another, or more generally the relative contributions of electricity and magnetism are dependent on the frame of reference. Thus, special relativity "mixes" electricity and magnetism into a single, inseparable phenomenon called electromagnetism, analogous to how relativity "mixes" space and time into spacetime.

Magnetic fields in a material[link]

In a vacuum,

Failed to parse (Missing texvc executable; please see math/README to configure.): \mathbf{B} \ = \ \mu_0\mathbf{H},

where μ₀ is the vacuum permeability.

In a material,

Failed to parse (Missing texvc executable; please see math/README to configure.): \mathbf{B} \ = \ \mu_0(\mathbf{H} + \mathbf{M}). \

The quantity μ₀M is called magnetic polarization.

If the field H is small, the response of the magnetization M in a diamagnet or paramagnet is approximately linear:

Failed to parse (Missing texvc executable; please see math/README to configure.): \mathbf{M} = \chi \mathbf{H},

the constant of proportionality being called the magnetic susceptibility. If so,

Failed to parse (Missing texvc executable; please see math/README to configure.): \mu_0(\mathbf{H} + \mathbf{M}) \ = \ \mu_0(1+\chi) \mathbf{H} \ = \ \mu_r\mu_0 \mathbf{H} \ = \ \mu \mathbf{H}.

In a hard magnet such as a ferromagnet, M is not proportional to the field and is generally nonzero even when H is zero (see Remanence).

Force due to magnetic field - The magnetic force[link]

Magnetic lines of force of a bar magnet shown by iron filings on paper

The phenomenon of magnetism is "mediated" by the magnetic field. An electric current or magnetic dipole creates a magnetic field, and that field, in turn, imparts magnetic forces on other particles that are in the fields.

Maxwell's equations, which simplify to the Biot-Savart law in the case of steady currents, describe the origin and behavior of the fields that govern these forces. Therefore magnetism is seen whenever electrically charged particles are in motion---for example, from movement of electrons in an electric current, or in certain cases from the orbital motion of electrons around an atom's nucleus. They also arise from "intrinsic" magnetic dipoles arising from quantum-mechanical spin.

The same situations that create magnetic fields — charge moving in a current or in an atom, and intrinsic magnetic dipoles — are also the situations in which a magnetic field has an effect, creating a force. Following is the formula for moving charge; for the forces on an intrinsic dipole, see magnetic dipole.

When a charged particle moves through a magnetic field B, it feels a Lorentz force F given by the cross product:^[10]

Failed to parse (Missing texvc executable; please see math/README to configure.): \mathbf{F} = q (\mathbf{v} \times \mathbf{B})

where

Failed to parse (Missing texvc executable; please see math/README to configure.): q

is the electric charge of the particle, and

v is the velocity vector of the particle

Because this is a cross product, the force is perpendicular to both the motion of the particle and the magnetic field. It follows that the magnetic force does no work on the particle; it may change the direction of the particle's movement, but it cannot cause it to speed up or slow down. The magnitude of the force is

Failed to parse (Missing texvc executable; please see math/README to configure.): F=qvB\sin\theta\,

where Failed to parse (Missing texvc executable; please see math/README to configure.): \theta

is the angle between v and B.

One tool for determining the direction of the velocity vector of a moving charge, the magnetic field, and the force exerted is labeling the index finger "V", the middle finger "B", and the thumb "F" with your right hand. When making a gun-like configuration, with the middle finger crossing under the index finger, the fingers represent the velocity vector, magnetic field vector, and force vector, respectively. See also right hand rule.

Magnetic dipoles[link]

A very common source of magnetic field shown in nature is a dipole, with a "South pole" and a "North pole", terms dating back to the use of magnets as compasses, interacting with the Earth's magnetic field to indicate North and South on the globe. Since opposite ends of magnets are attracted, the north pole of a magnet is attracted to the south pole of another magnet. The Earth's North Magnetic Pole (currently in the Arctic Ocean, north of Canada) is physically a south pole, as it attracts the north pole of a compass.

A magnetic field contains energy, and physical systems move toward configurations with lower energy. When diamagnetic material is placed in a magnetic field, a magnetic dipole tends to align itself in opposed polarity to that field, thereby lowering the net field strength. When ferromagnetic material is placed within a magnetic field, the magnetic dipoles align to the applied field, thus expanding the domain walls of the magnetic domains.

Magnetic monopoles[link]

Since a bar magnet gets its ferromagnetism from electrons distributed evenly throughout the bar, when a bar magnet is cut in half, each of the resulting pieces is a smaller bar magnet. Even though a magnet is said to have a north pole and a south pole, these two poles cannot be separated from each other. A monopole — if such a thing exists — would be a new and fundamentally different kind of magnetic object. It would act as an isolated north pole, not attached to a south pole, or vice versa. Monopoles would carry "magnetic charge" analogous to electric charge. Despite systematic searches since 1931, as of 2010^[update], they have never been observed, and could very well not exist.^[11]

Nevertheless, some theoretical physics models predict the existence of these magnetic monopoles. Paul Dirac observed in 1931 that, because electricity and magnetism show a certain symmetry, just as quantum theory predicts that individual positive or negative electric charges can be observed without the opposing charge, isolated South or North magnetic poles should be observable. Using quantum theory Dirac showed that if magnetic monopoles exist, then one could explain the quantization of electric charge---that is, why the observed elementary particles carry charges that are multiples of the charge of the electron.

Certain grand unified theories predict the existence of monopoles which, unlike elementary particles, are solitons (localized energy packets). The initial results of using these models to estimate the number of monopoles created in the big bang contradicted cosmological observations — the monopoles would have been so plentiful and massive that they would have long since halted the expansion of the universe. However, the idea of inflation (for which this problem served as a partial motivation) was successful in solving this problem, creating models in which monopoles existed but were rare enough to be consistent with current observations.^[12]

Quantum-mechanical origin of magnetism[link]

In principle all kinds of magnetism originate (similar to Superconductivity) from specific quantum-mechanical phenomena (e.g. Mathematical formulation of quantum mechanics, in particular the chapters on spin and on the Pauli principle). A successful model was developed already in 1927, by Walter Heitler and Fritz London, who derived quantum-mechanically, how hydrogen molecules are formed from hydrogen atoms, i.e. from the atomic hydrogen orbitals Failed to parse (Missing texvc executable; please see math/README to configure.): u_A

and Failed to parse (Missing texvc executable; please see math/README to configure.): u_B
centered at the nuclei A and B, see below. That this leads to magnetism, is not at all obvious, but will be explained in the following.

According the Heitler-London theory, so-called two-body molecular Failed to parse (Missing texvc executable; please see math/README to configure.): \sigma -orbitals are formed, namely the resulting orbital is:

Failed to parse (Missing texvc executable; please see math/README to configure.): \psi(\mathbf r_1,\,\,\mathbf r_2)=\frac{1}{\sqrt{2}}\,\,\left (u_A(\mathbf r_1)u_B(\mathbf r_2)+u_B(\mathbf r_1)u_A(\mathbf r_2)\right )

Here the last product means that a first electron, r₁, is in an atomic hydrogen-orbital centered at the second nucleus, whereas the second electron runs around the first nucleus. This "exchange" phenomenon is an expression for the quantum-mechanical property that particles with identical properties cannot be distinguished. It is specific not only for the formation of chemical bonds, but as we will see, also for magnetism, i.e. in this connection the term exchange interaction arises, a term which is essential for the origin of magnetism, and which is stronger, roughly by factors 100 and even by 1000, than the energies arising from the electrodynamic dipole-dipole interaction.

As for the spin function Failed to parse (Missing texvc executable; please see math/README to configure.): \chi (s_1,s_2) , which is responsible for the magnetism, we have the already mentioned Pauli's principle, namely that a symmetric orbital (i.e. with the + sign as above) must be multiplied with an antisymmetric spin function (i.e. with a - sign), and vice versa. Thus:

Failed to parse (Missing texvc executable; please see math/README to configure.): \chi (s_1,\,\,s_2)=\frac{1}{\sqrt{2}}\,\,\left (\alpha (s_1)\beta (s_2)-\beta (s_1)\alpha (s_2)\right )

,

I.e., not only Failed to parse (Missing texvc executable; please see math/README to configure.): u_A

and Failed to parse (Missing texvc executable; please see math/README to configure.): u_B
must be substituted by α and β, respectively  (the first entity means "spin up", the second one "spin down"), but also the sign + by the − sign, and finally ri by the discrete values si (= ±½); thereby we have Failed to parse (Missing texvc executable; please see math/README to configure.): \alpha(+1/2)=\beta(-1/2)=1
and Failed to parse (Missing texvc executable; please see math/README to configure.): \alpha(-1/2)=\beta(+1/2)=0

. The "singlet state", i.e. the - sign, means: the spins are antiparallel, i.e. for the solid we have antiferromagnetism, and for two-atomic molecules one has diamagnetism. The tendency to form a (homoeopolar) chemical bond (this means: the formation of a symmetric molecular orbital, i.e. with the + sign) results through the Pauli principle automatically in an antisymmetric spin state (i.e. with the - sign). In contrast, the Coulomb repulsion of the electrons, i.e. the tendency that they try to avoid each other by this repulsion, would lead to an antisymmetric orbital function (i.e. with the - sign) of these two particles, and complementary to a symmetric spin function (i.e. with the + sign, one of the so-called "triplet functions"). Thus, now the spins would be parallel (ferromagnetism in a solid, paramagnetism in two-atomic gases).

The last-mentioned tendency dominates in the metals iron, cobalt and nickel, and in some rare earths, which are ferromagnetic. Most of the other metals, where the first-mentioned tendency dominates, are nonmagnetic (e.g. sodium, aluminium, and magnesium) or antiferromagnetic (e.g. manganese). Diatomic gases are also almost exclusively diamagnetic, and not paramagnetic. However, the oxygen molecule, because of the involvement of π-orbitals, is an exception important for the life-sciences.

The Heitler-London considerations can be generalized to the Heisenberg model of magnetism (Heisenberg 1928).

The explanation of the phenomena is thus essentially based on all subtleties of quantum mechanics, whereas the electrodynamics covers mainly the phenomenology.

Units of electromagnetism[link]

SI units related to magnetism[link]

Other units[link]

• gauss – The gauss, abbreviated as G, is the CGS unit of magnetic field (B).
• oersted – The oersted is the CGS unit of magnetizing field (H).
• Maxwell – is the CGS unit for the magnetic flux.
• gamma – is a unit of magnetic flux density that was commonly used before the tesla became popular (1 gamma = 1 nT)
• μ₀ – common symbol for the permeability of free space (4π×10⁻⁷ N/(ampere-turn)²).

Living things[link]

Some organisms can detect magnetic fields, a phenomenon known as magnetoception. Magnetobiology studies magnetic fields as a medical treatment; fields naturally produced by an organism are known as biomagnetism.

See also[link]

References[link]

Further reading[link]

External links[link]

Wikibooks has a book on the topic of School science

Look up magnetism in Wiktionary, the free dictionary.

• Magnetism on In Our Time at the BBC. (listen now)
• The Exploratorium Science Snacks – Snacks about Magnetism
• Electromagnetism - a chapter from an online textbook
• Video: The physicist Richard Feynman answers the question, Why do bar magnets attract or repel each other?
• On the Magnet, 1600 First scientific book on magnetism by the father of electrical engineering. Full English text, full text search.

Adi Cristian Colceru also known as David Deejay (born December 10, 1980), is a DJ, producer and composer from Bârlad, Romania.^[1] He studied violin in school, but dropped his studies and began writing songs with the aid of a computer. After moving to Bucharest, he worked with several local producers, and in 2007 started with the hit single "Sexy Thing".^[2][3] David Deejay released several singles in the last years. He has a long time collaboration with Dony (Cornel Donici from the band Refflex).^[4] He is currently a student at the Romanian-American University, Faculty of trade and domestic and international financial and banking.^[5]

Biography[link]

Studies and beginnings in music[link]

Born in Bârlad, Colceru studied violin at a special school.^[5] He abandoned these studies, however, and at the age of 16 years started to mix songs on the computer.^[1] In 2003 he moved to Bucharest, where he composed songs at MOF Records for Akcent, TNT, 3rei Sud Est and Hi-Q.^[5]

David Deejay project[link]

Besides time spent in the studio, Colceru appeared as DJ in clubs under the name DJ David, and in this period he composed his first single "Sexy Thing" where he collaborated with Cornel Donici from the band Refflex which had the nickname "Dony".^[3][6] Colceru wanted the project to remain anonymous so not to be accused of plagiarism.^[6][7] His single, "Sexy Thing" reached the number 1 spot and stationed for five weeks in the Romanian Top 100^[8] and number 37 in the Bulgarian Top 100 where it stationed two weeks.^[9] In December 2009 he entered the Dutch Top 40 with "Sexy Thing". In Holland he lifts on the succes of Eastern European acts like Inna and Edward Maya. "Sexy Thing" won the award for Best Dance Play at the MTV Romania Music Awards 2008, ceremony held at Iaşi.^[10] The second single released, "Nasty Dream", was also a collaboration with Dony; the song peaked at number 1 in the top Romanian Top 100.^[11] On April 30, 2009, Colceru released two songs simultaneously being the first Romanian artist to do so.^[12] "I Can Feel" premiered at Vibe FM, with Ela Rose being the lead vocals that worked for this single, and "So Bizarre" (in collaboration with Dony) was presented for the first time at Radio 21.^[12] The "So Bizarre" single reached number 1 in the Romanian Top 100.

Discography[link]

Album[link]

• Ylies pato'w (2010)^[13]

All songs featuring Dony.

Singles[link]

Awards[link]

References[link]

External links[link]

• David Deejay at Last FM
• David Deejay at MusicMall.ro

Jessie J
Jessie J at the O2 Arena in London in 2011.
Background information
Birth name	Jessica Ellen Cornish
Also known as	Jessie J
Born	(1988-03-27) 27 March 1988 (age 24) Chadwell Heath, London, England, United Kingdom
Genres	pop, hip hop, R&B, dance-pop, soul
Years active	2005–present
Labels	Lava, Universal Republic, Island, Gut
Website	jessiejofficial.com

Jessica Ellen Cornish (born 27 March 1988), better known by her stage name Jessie J, is an English singer and songwriter. Born and raised in London, she studied at the BRIT School before signing with Gut Records and striking a songwriting deal with Sony/ATV Music Publishing where she wrote for artists such as Chris Brown and Miley Cyrus.

Signed with Universal, Jessie J came to prominence following the release of her debut single "Do It Like a Dude" which peaked at number two on the UK Singles Charts. After scoring her first number one in the United Kingdom, France, Ireland and New Zealand with the song "Price Tag", she released her debut album Who You Are (2011) which charted at number two in the UK. Other releases from the album include "Nobody's Perfect", "Who's Laughing Now" and "Who You Are" which charted within the top 20 in the UK but the release of fifth single "Domino" spawned international chart success, peaking at number 6 on the Billboard Hot 100 in the US, and becoming her second UK number one. Aside from her musical career, Jessie J is currently a coach and mentor on television show The Voice UK.

Citing various influences, Jessie J is recognized for an unconventional musical and performance style^[1][2] that mixes her soul voice with contemporary R&B, pop, and hip-hop influences. Jessie J has garnered various awards and nominations for her contributions to the music industry, including the 2011 Critics' Choice BRIT Award and the BBC's Sound of 2011. As of April 2012, Jessie has sold over 11 million singles and 2.5 million records worldwide.^[3][4]

Early life[link]

Jessie J was born Jessica Ellen Cornish in Chadwell Heath, London,^[5] daughter of Stephen Cornish and Rose Cornish (née Archer). She was educated at Mayfield High School in the London Borough of Redbridge. She attended Colin's Performing Arts School and as an 11-year old-was cast in Andrew Lloyd Webber's West End production of Whistle Down the Wind.^[6][7][8] Jessie has two sisters, who are five and seven years older than her, who were both head girls at school. Unlike her academic sisters, Cornish has stated she was "never really that good at anything". She said, "At school they were like 'oh, you're a Cornish girl' and they kind of expected me to be the same as my sisters. Give me something to draw or an outfit to pick for someone, or hair, make-up, acting, write a song, I'm fine with it, but anything to do with sums – it was never my thing." She also said she never based her intelligence on her exam results.^[9] She also said she was always good at singing and it was her "thing". At the age of 16 she began studying at the BRIT School and at 17 she joined a girl group named Soul Deep.^[10] She graduated in the class of 2006 along with singers Adele and Leona Lewis.^[11] At 18 she suffered a stroke.^[12]

Music career[link]

2006–2010: Career beginnings[link]

Jessie J was signed to Gut Records, recording an album for the label, but the company went bankrupt before any material was released.^[8][10] She then found success as a songwriter, gaining a Sony ATV publishing contract.^[13] She was also the support act for Cyndi Lauper during Lauper's UK dates of her 2008 Bring Ya To The Brink tour (Lauper invited J to join her on stage for the performances of "Girls Just Want To Have Fun"). Jessie has also written lyrics for artists such as Chris Brown and Miley Cyrus, including "Party in the U.S.A.".^[14][15] Jessie J was also part of a girl band, called Soul Deep, for two years, however she left due to thoughts that "it wasn't going anywhere". Despite people thinking that her first notoriety was through YouTube, Jessie was signed for four years before her first video was posted. Jessie first came to the attention of Lava Records when her publisher at Sony/ATV, Rich Christina, sent Lava president Jason Flom a link to her MySpace page, which the record executive loved.^[16] After seeing an impressive U.S. showcase, Lava was, along with several other labels, keen to sign the artist but progress was hampered by her management's insistence on, what Flom called, a "crazy deal", and their refusal to let Jessie speak to any labels directly.^[16] Despite this, Senior Director of A&R at Lava, Harinder Rana, made surreptitious efforts to meet Jessie on her own in winter of 2008. Later in the year a change in management to Sarah Stennett and Nadia Khan of Crown Music allowed record deal negotiations to take place. Jessie eventually signed with Lava as part of a joint venture with Universal Republic.^[16]

[edit] 2010–2012: Who You Are

Jessie J performing at a concert in New York City in 2011.

Jessie J began recording her debut studio album in 2006 and it was completed on 19 January 2011.^[17][18] She revealed that "Big White Room" would be on the album and was written from an experience she had when she was 11 years old, although she wrote the song at age 17, in hospital, where a ward mate, a little boy, died.^[19] Jessie J says the album's title track, "Who You Are", is one of her proudest creations, she said the song is a "positive role model for young people" and "I always say that I'm half-artist, half-therapist".^[19] In late 2010 Jessie J released her first single, "Do It Like a Dude" which was co-written with George Astasio, Tj Normandin, Jason Pebworth, Jon Shave, Kyle Abrahams and Peter Ighile. Originally, she wrote the song with Rihanna in mind because "Rude Boy" was released at the time, partly inspiring the song. She then sent the song to her label, Island Records, before sending it to Rihanna's management. Island insisted the song become Jessie J's first single.^[20] She wishes to perform the song with Rihanna at one point.^[21] The single gained positive reception from critics.^[22] The single charted at number two on the UK Singles Charts. Her follow-up single "Price Tag" was released in late January 2011. This was written by Jessie J, Lukasz Gottwald, Claude Kelly, and Bobby Ray Simmons, Jr. and charted at number one in the top of the charts. "Price Tag" was released in the United States on 1 February 2011 and peaked at 23 on the Billboard Hot 100.^[23] "Price Tag" also charted at number-one in New Zealand and Ireland and is the most successful online video J has released. As of October 2011, the video has generated over 148 million views on Youtube and Vevo, making it the 22nd most viewed music video of all time.^[24][25] Her first American television appearance was as the musical guest on the 12 March 2011 episode of NBC's Saturday Night Live.^[26]

On 25 February 2011 her debut album, Who You Are, was released.^[27] The album first entered the charts on 6 March 2011 where it charted on the UK Album Charts at number two. The album charted into the top ten in a number of countries and number 11 in the United States.^[28] After the release she went on to release a third single from the album, "Nobody's Perfect".^[29] MTV reported that the single is, so far, only confirmed for release in the United Kingdom.^[30] The album's fourth single was "Who's Laughing Now". "Domino" was her second US single.^[31] The Dr. Luke-produced track was sent to mainstream radio on 6 September 2011.^[32] With the success of Who You Are in North America, Jessie was chosen to tour as the opening act for American pop artist Katy Perry's California Dreams Tour in 2011 but after she was unable to fully recover from her injuries during rehearsals she was forced to pull out under the doctor's orders.^[33] Jessie J served as the house artist at the 2011 MTV Video Music Awards, performing several of her original songs along with covers around commercial breaks.^[34]

James Morrison's third studio album, The Awakening features a collaboration with Jessie J called "Up", the song was released as a single on 4 December 2011. Jessie J re-released "Who You Are" on 9 November 2011, featuring the regular tracks plus "Domino" and two new songs. "Domino" became her first top 10 hit in the U.S., following the success of "Price Tag". The song also peaked at number 1 in January 2012 in the UK, before it was even officially released there.

[edit] 2012–present: Second studio album and The Voice

On 4 October 2011, Jessie announced that she will be one of four coaches for new BBC program, The Voice UK.^[35] The show was announced after the success of the US version, The Voice. It premiered in March 2012 on BBC One. It will be presented by Holly Willoughby and Reggie Yates, with will.i.am (of The Black Eyed Peas), Tom Jones and Danny O'Donoghue (of The Script) joining Jessie on the coaching panel.^[36] The first stage of the competition, The Blind auditions, began in London on 18 January 2012 at the BBC Television Centre and finished filming on 22 January 2012. The winner will receive £100,000 and a record deal with Universal Republic. It was also reported that the 4 coaches recorded a cover of the Black Eyed Peas song, "I Gotta Feeling", and will release an accompanying music video to help promote the show.^[37]

On 31 January 2012, Jessie announced that she had begun recording for her second studio album.^[38] She also stated that she hopes to collaborate with many artists this year, possibly including some of her fellow coaches on The Voice.^[39] It was revealed that she has worked in the studio with Cee-Lo Green after he tweeted her on twitter. Jessie has also revealed on twitter that she has worked with Diane Warren as well as reuniting in the studio with her 'Price Tag' co-writer Claude Kelly.

Jessie will embark on her first arena tour in March 2013. Via microblogging website, Twitter, Jessie J confirmed the tour will be called Nice to Meet You Tour.^[40]

Personal life[link]

Jessie J performing at the 2011 The Big Chill, sitting on the "gilded throne" she used for performances while her foot was broken.

In early 2011 she suffered a panic attack on stage after she was forced to perform in the dark. "I did a gig recently and had a panic attack on stage," she told NOW. "The night was called 'Black Out' and I had to perform in the dark. I asked them to turn on the lights and they didn't. I was onstage in pitch black and, because I couldn't see anything, I started to panic. It was awful."^[41]

Jessie J is bisexual and stated in an interview on the "In Demand" radio show on 3 March 2011, "I've never denied it. Whoopie doo guys, yes, I've dated girls and I've dated boys – get over it."^[42][43] However, in April 2012 The Sun outed her as homosexual which she denied via Twitter, calling it a "yet another boring untrue story".^[44] According to The Guardian, Jessie J's sexuality is valuable to young teens, especially for young girls unsure of themselves because of their sexuality and identity, to feel "that this does happen and this is normal."^[45]

On 12 June 2011 at the Capital Radio Summertime Ball, Jessie ruptured several tendons in her foot during rehearsals, and performed her set the following day while sitting on a gilded throne.^[46] For her appearance at Glastonbury Festival 2011 on 25 June 2011, she performed on the throne again, claiming her physician had told her not to perform with her broken foot which would take six weeks to heal.^[47] Jessie J was scheduled to play at several festivals throughout the summer, however it was reported on 1 July 2011 that she would not be able to attend T in the Park, T4 On The Beach, Wembley:Orange, iTunes Festival, Lovebox and Oxegen due to the injuries to her foot. Jessie J personally tweeted before surgery; "Keep making nervous jokes with the doctor and he keeps looking at me blankly. Which is making me laugh even more. It's getting serious. I just took my nose stud out." Tweeting after the surgery, she wrote: "Can't keep tweeting. Still very dizzy and being sick. But I'm OK, I got through it." Her record label released an official statement on 30 June 2011 that under strict orders from her doctor, she will not be able to perform for a number of weeks so she can heal and recuperate properly.^[48] She returned to the concert circuit in late August, including sets at the V Festival^[49] and The Big Chill. For the 2011 VMA's she was still in a cast and using the throne to keep off it.

Jessie J confirmed on 2 August 2011 that she would be shaving her hair off for charity in 2012. Speaking via her official Twitter account she said: "It’s hair, It will grow back. Even if it takes 2 years, if it saves lives it’s worth it. Even if its 1 life that’s something."^[50]

‎Artistry and voice[link]

Jessie J performing at the Bournemouth International Centre in 2011.

Although she was first identified as a soul singer, she primarily records songs of contemporary R&B and pop music with hip-hop influences.

Music critic Matthew Perpetua of Pitchfork Media compared Jessie J to her peers Adele and Amy Winehouse, but suggested she was missing something: "Whereas Adele and Winehouse also have powerhouse voices, they fit into clear aesthetic niches and invest their songs with depth and humanity. Jessie J doesn't have even a fraction of their restraint." Perpetua added: "Her idea of showcasing her gift is to shoot for a blaring melisma on "Mamma Knows Best" that makes Christina Aguilera seem as subtle as Joni Mitchell by comparison."^[51]

Ailbhe Malone of the music magazine NME also recognized Cornish's "undeniably potent voice". However, she pointed out the possible "identity crisis" that might have been caused by Jessie's songwriter past: "This is an album of singles for other artists. There’s Rihanna Jessie (‘Do It...’), Perry Jessie (‘Abracadabra’), Pixie Jessie (‘Mamma Knows Best’), Ellie Jessie ('Big White Room')."^[52]

Caroline Sullivan of The Guardian shared her positive opinion about the singer, saying that "if any singer has the potential to be the British Katy Perry or Pink, with the accompanying millions of sales, it's her". Sullivan also complimented Cornish's attitude: "[Her songs] are delivered with a confidence that money can't buy."^[53]

Entertainment Weekly's music critic Adam Markovitz said of Jessie: "The 23-year-old Brit has all the tools, from a monster voice to an ear for hooks — she co-wrote Miley Cyrus' 'Party in the U.S.A.' — and a manic persona that's equal parts Katy Perry, Kristin Chenoweth, and Alice Cooper."^[54]

Discography[link]

• Who You Are (2011)

Concert tours[link]

Headlining

• Stand Up Tour (2011)
• Heartbeat Tour (2011-12)
• Nice To Meet You Tour (2013)

Filmography[link]

Awards and nominations[link]

References[link]