What is Diamagnetism: Definition and 36 Discussions

Diamagnetic materials are repelled by a magnetic field; an applied magnetic field creates an induced magnetic field in them in the opposite direction, causing a repulsive force. In contrast, paramagnetic and ferromagnetic materials are attracted by a magnetic field. Diamagnetism is a quantum mechanical effect that occurs in all materials; when it is the only contribution to the magnetism, the material is called diamagnetic. In paramagnetic and ferromagnetic substances, the weak diamagnetic force is overcome by the attractive force of magnetic dipoles in the material. The magnetic permeability of diamagnetic materials is less than the permeability of vacuum, μ0. In most materials, diamagnetism is a weak effect which can be detected only by sensitive laboratory instruments, but a superconductor acts as a strong diamagnet because it repels a magnetic field entirely from its interior.

Diamagnetism was first discovered when Anton Brugmans observed in 1778 that bismuth was repelled by magnetic fields. In 1845, Michael Faraday demonstrated that it was a property of matter and concluded that every material responded (in either a diamagnetic or paramagnetic way) to an applied magnetic field. On a suggestion by William Whewell, Faraday first referred to the phenomenon as diamagnetic (the prefix dia- meaning through or across), then later changed it to diamagnetism.A simple rule of thumb is used in chemistry to determine whether a particle (atom, ion, or molecule) is paramagnetic or diamagnetic: If all electrons in the particle are paired, then the substance made of this particle is diamagnetic; If it has unpaired electrons, then the substance is paramagnetic.

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  1. hongseok

    I Does Diamagnetism Occur Even in a Constant Magnetic Field?

    I learned that diamagnetism is due to Lenz's law. But doesn't Lenz's law only apply when the magnetic field changes? Why does diamagnetism occur even when a constant magnetic field is applied without change?
  2. I

    Directing magnetic field lines by using diamagnetic material

    I want to improve the magnetic field strength at the surface of a magnet configuration by utilizing diamagnetic materials to guide the magnetic field lines. I have not the proper equipment to measure the effect myself but would this work? This is the initial configuration with four magnets side...
  3. W

    I Magnetization inside a diamagnetic material antiparallel to ##B_{ext}##

    Let's say I have a constant magnetic field and I dive into it a diamagnetic material. Griffiths says that in the presence of a magnetic field, matter becomes magnetized and it will be found to contain many tiny dipoles with a net alignment along some direction. However, what's exactly the link...
  4. jaumzaum

    B Is diamagnetism only present with varying magnetic fields?

    Hello. I was wondering if diamagnetic materials only repel varying electric field? By Ampere law only a variable flux can cause an electromotive force, so, and by what I understood diamagnetism is explained exclusively by Ampere law. Am I wrong?
  5. R

    Is a diamagnetic levitation engine possible?

    I recently saw the video of the frog being levitated with a big magnet. Would it be possible to flip the magnet over and use it to levitate a vehicle? How much energy would it take to levitate, say, a 1000kg vehicle above a dry lakebed?
  6. M

    Diamagnetism & levitation of pyrolytic graphite explanation

    Hi, This YouTube video shows various shapes of pyrolytic graphite suspended on an alternating polarity matrix of square neodymium magnets. As I understand the principle of diamagnetic anisotropy, the stronger the external magnetic force, the stronger the induced repulsive force in the...
  7. C

    Can diamagnetism be created electrically

    I was wondering if diamagnetism can be created electrically or does the material have to be diamagnetic in nature?
  8. K

    Diamagnetic material's response to temperature change

    I know that in a para magnetic material the magnetization increase on cooling. What will be the same effect on a diamagnetic material,considering the fact that Curies law doesn't hold good on diamagnetic materials.
  9. J

    Diamagnetism experiment with copper/lead

    I'm new to the concept of diamagnetism, but it seems very fascinating, and I'd like to try a simple experiment. Say I wanted to repel a small piece of lead (or copper, both are readily available to me) about 3.5 grams, how strong of a magnet would I need? Could I just use small neodymium magnets...
  10. chikou24i

    A Landau Diamagnetism Explained: Free Electron Gas

    Hi, in the case of free electrons gas under the effect of a magnetic field. The hamiltonian of an electron doesn't contain a term of Spin-Magnetic field interaction this means that it contains just the kinetic energy terms. Why is that ?
  11. G

    Diamagnetism Mechanism: Questions Answered

    Friends! I have some things unclear about diamagnetism in matter.Please see attached picture.
  12. Robert100

    How does diamagnetism originate?

    For AP Physics or Chemistry, how do we explain the origin of magnetism, and diamagnetism? Saying that "Well, it's a quantum mechanical effect" or "it is a relativistic effect" isn't much help in explaining it's origin. Are there semi-classical explanations or analogies, that high school seniors...
  13. P

    I Diamagnetism vs. paramagnetism in solid state

    I am studying some solid state physics, in particular magnetism; I have a few questions about the explanations. My understanding is that paramagnetism is primarily an effect of the electron's spin-angular momentum: an unpaired electron will have a dipole moment which preferentially aligns with...
  14. HelloCthulhu

    Diamagnetism and Hydrogen Bond Strength

    I've read a few papers regarding the effects of a uniform magnetic field on water solutions, but I'm a complete illiterate when it comes to deciphering the jargon. So far, many papers confirm that a uniform magnetic field strengthens hydrogen bonds and can increase the redox potential. I've...
  15. C

    What causes paramagnetism and diamagnetism

    Paramagnetism: How does having an unpaired electron attract it into a magnetic field. Why not repel? Is there any reason or we just know from experiment? Diamagnetism: If the electron spins and therefore magnetic fields cancel, what is causing it to repel from a magnetic field? If it is...
  16. AdityaDev

    Diamagnetism and orbital magnetic moment

    For diamagnetic materials, when an external magnetic field is applied, the electrons having orbital magnetic moment in opposite directions spped up. how does this happen? The direction of magnetic momwnt is given by right hand thum rule. If there is an electron revolving in anticlockwise...
  17. I

    How Do Unpaired Electron Orbits React to External Magnetic Fields?

    Please confirm & answer the following: An atom exposed to an external B-field will experience both a torque on its orbitals (paramagnetism), and a change in orbital velocities and thereby a change in the magnetic momenta of the orbits (diamagnetism). When the atom has all paired electrons...
  18. F

    Does diamagnetism cause a faster orbital spin

    Due to diamagnetism in certain substances such as water, does this cause a faster orbital spin due to the change in magnetic dipole moment induced by an external magnet? I'm doing a Science-fair project at the moment and this is eluding me Thank you
  19. N

    Why are most of the ionic crystals Diamagnetism

    Why are most of the ionic crystals Diamagnetism ?? Ionic crystals are those crystals that are related to ionic bonds of atoms such as sodium chloride NACL
  20. S

    What is the cause for diamagnetism and other types of magnetism?

    What is the cause for diamagnetism and other types of magnetism? Is it related to Farady's law or quantum mechanical properties of matter?
  21. H

    How Does the Ising Model Exhibit Diamagnetism to Paramagnetism Transition in 2D?

    I'm doing a computational physics project where I'm looking at the Ising model in 2D and external magnetics field. I start with all the spins in same directions my grid is 30x30 and I use periodic boundry conditions. I start with all the spins in the same direction (+1). I do about 150000...
  22. G

    Lamor precession and diamagnetism

    i have some troubles to understand the lamor precession properly and i need your help to correct my errors: so in order to get the lamor precession: afaik you need something that causes a magnetic moment, e.g. an electron with spin or angular momentum. then you need a homogenous magnetic field...
  23. C

    Bismuth vs aluminum diamagnetism

    a few weeks ago i bought a number of pieces of 'bismuth' bullions... i already own a piece of aluminum , as well as a few neodymium magnets if i place the magnet on the aluminum and tilt the aluminum to make the magnet slide off, it will encounter some opposing force from eddy currents and...
  24. A

    What is the Role of Lenz's Law in Diamagnetism?

    Can anyone explain what is the cause of diamagnetism... to the extent i know is that the paired electron with opposite spin cancel out each other's magnetic moment... is there something more to this...? and on application of external magnetic filed why does it repel it... thanks for...
  25. G

    How Do Diamagnetism and Magnetism Differ from Gravity?

    Hello, Been trying for more than a while to understand the idea of Diamagnetism and can't seem to grasp it (not that surprising since i know nothing of physics). If gravity and magnetism are two completely different forces which cases different reactions and are cased by different things...
  26. P

    Diamagnetism is the property of an object

    Diamagnetism is the property of an object which causes it to create a magnetic field in opposition of an externally applied magnetic field, thus causing a repulsive effect. This is property of all materials. But can be perceive only for materials which atoms or ions have closed shells. Examples...
  27. J

    The difference between diamagnetism and paramagnetism?

    Hi, I am struggling to see the difference in the origins of diamagnetism and paramagnetism. My understanding of things is that the electrons orbitting an atom constitute a tiny circular current loop, which corresponds to a magnetic dipole moment pointing normal to the plane of that loop...
  28. S

    What is magnetism, diamagnetism and paramagnetism?

    I need help understanding both of these terms. I know that diamagnetism is when the valence electrons of the material are paired and repel a magnetic field. Does that mean it repels like the North side of a magnet to another North side of a magnet? Or is it they don't attract at all...
  29. H

    Difference between Perfect Diamagnetism and Superconductors

    Could someone please explain the difference between Perfect Diamagnetism and Superconductors in terms of the Meissner Effect and the magnetic field passing through an element of the sort. Under low temperatures in perfect diamagnetic materials if there is a magnetic field it remains the same...
  30. C

    Perfect Diamagnetism: Properties Necessary for Ideal State

    What properties would an ideal ("perfect") diamagnet necessarilly* have? (*as in in, implied by definition.) This is a spin-off from https://www.physicsforums.com/showthread.php?t=198245", based on the common idea that superconductors are better described as perfect diamagnets than perfect...
  31. M

    Exploring Classical Diamagnetism: Understanding its Limitations in Mechanics

    Why diamagnetism can't occur in classical mechanics? Where can I know more about that? Thanks
  32. P

    Explaining paramagnetism, diamagnetism, and ferromagnetism

    I have a short paper to write this weekend and my physics book doesn't do a very good job of explaining paramagnetism, diamagnetism, and ferromagnetism. Anyone know a good website that gives similarities and differences among those 3 types of magnetism? Thank you.
  33. I

    Diamagnetism of Pyrolytic carbon

    We know that http://en.wikipedia.org/wiki/Pyrolytic_carbon" layers will have an omni directional cleavage and possibly an omni directional Diamagnetic field. Also, could a http://www.ebteccorp.com/lasercut.html" cut such a thin sheet of Pyrolytic carbon to transparent thickness, If not then...
  34. Mk

    After a certain external field strength Diamagnetism can collapse?

    After a certain external field strength can it collapse?
  35. N

    Report on either Diamagnetism or Paramagnetism

    I am doing an extra-credit report on either Diamagnetism or Paramagnetism, just wondering if any of you can give me any resources on either subject.
  36. A

    Diamagnetism vs. paramagnetism

    Simple question, kind of. I know that paramagnetic materials, when in the presence of a magnetic field will have its dipoles orient with the field while diamagnetic materials when introduced to a magnetic field orient opposite to the field. I've read that this has something to do with Lentz's...