What is Susceptibility: Definition and 79 Discussions

In electromagnetism, the magnetic susceptibility (Latin: susceptibilis, "receptive"; denoted χ) is a measure of how much a material will become magnetized in an applied magnetic field. It is the ratio of magnetization M (magnetic moment per unit volume) to the applied magnetizing field intensity H. This allows a simple classification, into two categories, of most materials' responses to an applied magnetic field: an alignment with the magnetic field, χ > 0, called paramagnetism, or an alignment against the field, χ < 0, called diamagnetism.
Magnetic susceptibility indicates whether a material is attracted into or repelled out of a magnetic field. Paramagnetic materials align with the applied field and are attracted to regions of greater magnetic field. Diamagnetic materials are anti-aligned and are pushed away, toward regions of lower magnetic fields. On top of the applied field, the magnetization of the material adds its own magnetic field, causing the field lines to concentrate in paramagnetism, or be excluded in diamagnetism. Quantitative measures of the magnetic susceptibility also provide insights into the structure of materials, providing insight into bonding and energy levels. Furthermore, it is widely used in geology for paleomagnetic studies and structural geology.The magnetizability of materials comes from the atomic-level magnetic properties of the particles of which they are made. Usually, this is dominated by the magnetic moments of electrons. Electrons are present in all materials, but without any external magnetic field, the magnetic moments of the electrons are usually either paired up or random so that the overall magnetism is zero (the exception to this usual case is ferromagnetism). The fundamental reasons why the magnetic moments of the electrons line up or do not are very complex and cannot be explained by classical physics. However, a useful simplification is to measure the magnetic susceptibility of a material and apply the macroscopic form of Maxwell's equations. This allows classical physics to make useful predictions while avoiding the underlying quantum mechanical details.

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  1. P

    Absorption coefficient and Linear Optical Susceptibility

    ##\alpha## is considered to be the absorption coefficient for a beam of light of maximum intensity ##I_0##. It's related to the complex part of the refractive index as we have shown above. Now, I have a doubt. Should I solve for ##k## from the quadratic equation in terms of the linear optical...
  2. Like Tony Stark

    Partial derivatives of enthelpy and Maxwell relations

    I've attached images showing my progress. I have used Maxwell relations and the definitions of ##\alpha##, ##\kappa## and ##c##, but I don't know how to continue. Can you help me?
  3. S

    Fourier transform of electric susceptibility example

    I have not studied the Fourier transform (FT) in great detail, but came across a problem in electrodynamics in which I assume it is needed. The problem goes as follows: Evaluate ##\chi (t)## for the model function...
  4. Cryo

    A Nonlinear susceptibility and group reps

    Dear All short explanation: I am trying to leverage my limited understanding of representation theory to explain (to myself) how many non-vanshing components of, for example, nonlinear optical susceptibility tensor ##\chi^{(2)}_{\alpha\beta\gamma}## can one have in a crystal with known point...
  5. I

    Nonlinear Optics: third-order susceptibility

    Hi. I've just learned about enumerating the second-order susceptibility (rather blindly) by 3^3 * (3*2*1) * 2 = 324. (tensor size * 3 frequency permutation * negative frequency) I'm guessing that for the third-order susceptibility would similarly yeild 3^4 * (4*3*2*1) * 2 = 3888? I couldn't...
  6. Q

    A Susceptibilites for the Anderson Impurity Model

    My question is a rather general one about susceptibilities but specific answers for the Anderson Impurity Model are also appreciated. In this paper https://arxiv.org/abs/1101.2840 (was also published in the Journal of Physics: Condensed Matter...
  7. Charles Link

    Susceptibility of Ferromagnetic materials

    A complete table of the ac susceptibility ## \chi_m ## of various ferromagnetic materials, where ## M=\chi_m H ##, is something that I have had trouble finding in a google of ferromagnetic materials. In what I have been able to come up with to date, there is quite a spread in the values of...
  8. C

    Find magnetic susceptibility using partition function

    Homework Statement A certain magnetic system contains n independent molecules per unit volume, each of which has four energy levels given by 0, ##Δ-gμ_B B##, ##\Delta##, ##\Delta +gμ_B B##. Write down the partition function, compute Helmholtz function and hence compute the magnetization ##M##...
  9. MathematicalPhysicist

    Susceptibility of a simple metal (Problem 31.6 in Ashcroft's

    Homework Statement The susceptibility of a simple metal has a contribution ##\chi_{c.c}## from the conduction electrons and a contribution ##\chi_{ion}## from the diamagnetic response of the closed-shell core electrons. Taking the conduction electron susceptibility to be given by the free...
  10. ReidMerrill

    Magnetic Susceptibility and Unpaired electrons

    Homework Statement I'm am trying to find out the magnetic susceptibility,XM in order to calculate the number of unpaired electrons in Mn(acac)3 via the Evans Method Homework Equations XM = (477) Δv/(Qv1C) XM= X'm+ XM(metal)+ XM (ligands) Where X'M is the magnetic susceptibilty of just the...
  11. Konte

    I Hyperpolarizability and second order susceptibility

    Hello everybody, My question is about nonlinear optic in both macroscopic and microscopic point of view. What is the relationship between second order susceptibility tensor \chi^{(2)} and the first hyperpolarizability tensor \beta ? Thank you everybody. Konte.
  12. M

    Using the complex susceptibility in E dot J

    Homework Statement Use the complex susceptibility to prove that the dot product of E and J is related to the absorption term (the imaginary part - χ'') and independent of the real part (χ'). It is also stated that in order to do is, assume monochromatic field and take the absorption time...
  13. J

    Calculate superconductor's magnetic susceptibility from Inductance

    Homework Statement Hi, I have some data taken on voltage and resistance of a coil part of a yttrium barium copper oxicde (ycbo) superconductor. I have no information about the coil itself. A thermocouple attached to the superconductor also measured the temperature of it as it was cooled. This...
  14. DeathCheese

    Calculate force on Permanent Magnet near a Paramagnetic surface

    Hello all, new here but plan to stick around for a while. I am currently trying to make a sensor that can detect if a material below it is paramagnetic. I believe paramagnetic is the proper term, but it needs to detect if the force exerted by permanent magnet is above a certain threshold. The...
  15. Keith

    Magnetic permeability Vs. Magnetic susceptibility

    Hi I'm trying to find the difference between magnetic susceptibility and permeability? Do they both mean the same thing? If not, can anyone clear things up for me?
  16. Y

    Nonlinear electric susceptibility and degenerate frequencies

    Hi there, I'm having a little trouble understanding the "distinguishability" of frequencies in the nonlinear electric susceptibility tensor. As far as I understand, if we have a SHG process with two collinear beams of the same polarization and frequency ω, there is only one susceptibility...
  17. E

    Magnetic Susceptibility Tabulated Values

    Hey, sorry if this is in the wrong section. I am looking for a tabulated value magnetic susceptibility of some metal salts; Sodium thiosulfate in particular. Could someone point me in the right direction? Thanks
  18. Konte

    Nonlinear susceptibility in second harmonic generation

    I have read a book that demonstrate the origin of electrical susceptibility of high order in harmonic generation: (in Robert Boyd's book : "Nonlinear optics"). For example, he show clearly for the case of second harmonic generation, how \chi^{(2)} depends on matrix element of electric dipole...
  19. U

    Curie-Weiss Paramagnetism susceptibility

    Homework Statement (a) Show the curie-weiss behaviour. (b) Estimate ##\lambda## and ##B_e## and exchange energy.[/B] Homework EquationsThe Attempt at a Solution Part(a) Since even when applied field is zero, ##B_{total} \neq 0## which gives rise to ##M\neq 0##. This is a fundamental...
  20. U

    Magnetic Susceptibility and Curie Temperature

    Homework Statement Part(a): Derive susceptibility Part(b): Find field experienced by neighbour. Part(c): State temperature range. What explains temperature dependence beyond curie temperature? Why is curie temperature so high? Part(d): In practice, measured magnetic moment is far lower than...
  21. L

    Magnetic susceptibility of Superconductor

    as we know, B=0 in superconductors, because of Messner effect. B=μ0(H+M) => H=-M => χ=-1 in CGS units: B=H+4πM => H=-4πM χ=-1/4π --- question: why χ=-0.01 not χ=-1/4π for 100% superconductors? :frown::oldshy:
  22. Konte

    Quantum treatment of nonlinear susceptibility

    Hi everybody, In Robert W. Boyd's book "Nonlinear Optics", the quantum treatment of the nonlinear optical susceptibility lead to the next expression, for the second order case: \chi^{(2)}_{ijk}(\omega_{\sigma},\omega_q,\omega_p)=\frac{N}{\hbar^2} P_F\sum_{mn}...
  23. A

    What can be found in the MT curves of superconductors?

    I am confused about the magnetic susceptibility vs. temperature curves (or MT) of superconductors (SCs). In the normal conduction state (I measured from 4.5K to 300K), the susceptibility curve can obey the Curie-Weiss law. But when I fitted the data via the Curie-Weiss law in a different...
  24. M

    Magnetic susceptibility integral trouble

    Hello, This is really more of an algebra question. Here is the main integral I am using for the susceptibility V\chi_0=\frac{d\langle...
  25. S

    Analytic verification of Kramers-Kronig Relations

    Homework Statement Show that the real and imaginary parts of the following susceptibility function satisfy the K-K relationships. Use the residue theorem. $$ \chi(\omega) = \frac{\omega_{p}^2}{(\omega_0^2-\omega^2)+i\gamma\omega} $$ Homework Equations The Kramers-Kronig relations are $$...
  26. HelloCthulhu

    Magnetic Susceptibility and Magnetization of Water

    This thread coincides with a previous thread I posted on reddit: http://www.reddit.com/r/chemistry/comments/2g69vt/magnetohydrodynamics_internal_energy_and_system/ I'm trying to solve the following equation: U=TS-PV+HM. The problem is I'm having difficulty solving H delta M. I was told H is...
  27. O

    Susceptibility of medically implanted chips to EMP

    The medical industry is starting to move towards miniature implanted electronic devices for monitoring the body, automatically delivering drugs to the body, and tracking senile patients. My question is , aren't these vulnerable to EMP , In a nuclear attack patients would have their drug...
  28. F

    Magnetic susceptibility

    This is defined by M=XmH. Using H=(B/u0)-M to eliminate M gives us M=1/u0(Xm/1+Xm)B, where B is the total magnetic field. Now my problem is, my book states that for paramagnetic media, Xm is positive, and for diamagnetic media Xm is negative. Now for paramagnetism, we expect M and B to have...
  29. G

    Where do I find Nonlinear Susceptibility Tensor Values?

    Hi, everyone. I am having a hard time finding explicit values of non-linear susceptibility tensor values for any sort of crystals. Specifically, I'm looking for values of a BBO crystal, but I would like to know where to find others for my future research. I should say that I am looking for the...
  30. Greg Bernhardt

    What is susceptibility in physics?

    Definition/Summary Susceptibility is a property of material. In a vacuum it is zero. Susceptibility is an operator (generally a tensor), converting one vector field to another. It is dimensionless. Electric susceptibility \chi_e is a measure of the ease of polarisation of a material...
  31. R

    Calculating magnetic susceptibility from the g factor

    revision already calculated J to be 15/2 have already found g to be 1.33 M = ngμJ magnetic suseptibilty is 5X10^-7 m^3/mol please could omeone tell me if it is possible to calculate the magnetic susceptibility from the above information? thanks in advance for an pointers.
  32. R

    Isothermal Magnetic Susceptibility

    My book says that "in the mean field approximation, the isothermal magnetic susceptibility just below the Curie temperature goes as ##(T_c-T)^{-1}##". I need some help understanding how to get this proportionality. My book does not contain any derivation or further explanations. According to...
  33. E

    Why does second order susceptibility become zero in centrosymmetric media?

    Hello everyone I just want to ask why In a centrosymmetric media the media doe not change why going from r to -t r is a position vector thus Second order susceptibility becomes zero ?? Thank you
  34. M

    Magnetic susceptibility and relative permeability

    Homework Statement find the derivation of χm=μr-1 where Xm is the magnetic susceptibility and μ is the relative permeability. Homework Equations M=Xm.H M is the magnetization,H is the magnetic field μr=μ/μo where μo is the permeability of a vacuum, The Attempt at a Solution I...
  35. djh101

    Gouy Balance Nonlinear Slope (Magnetic Susceptibility Lab)

    I am currently analyzing my data for the physical chemistry magnetic susceptibility lab. All the data is giving nice, smooth graphs for force vs. current, but I am unable to linearize them. F = \frac{1}{2}\chi\mu_{0}AH^{2} I have plotted force vs. current and force vs. current squared...
  36. ShayanJ

    Question on a simple caluclation of electric susceptibility

    The simplest model for calculating electric susceptibility of dielectrics,is a driven oscillation of an electric dipole with a resistive force proportional to its velocity.Its equation is like below: m\ddot{x}+\gamma \dot{x}+kx=-eE We know that the restoring force is the same force binding...
  37. S

    Magnetization and magnetic susceptibility

    For magnetization which can be written as \vec{B} = μ(o) (\vec{H} + \vec{M}) , how would it be expressed as a function of N (number density N atoms per unit volume), μ , magnetic-field Bo, T, and some constants (Boltzman's constant, Curie constant)? I have found similar set ups from different...
  38. S

    Thermodynamics - specific heats and electric susceptibility

    Homework Statement Calculate the difference of specific heats ##c_E-c_P## of oil with density ##800 kg/m^3## at ##T=27 °C## in electric field with ##E=10^7V/m##. In this conditions the electric susceptibility is 2 and is a function of T given as ##\frac{\chi }{\chi +3}\propto 1+\frac{C}{T}##...
  39. C

    Calculation of Electric Susceptibility In Solids.

    I'm curious what models there are for calculating the Electric Susceptibility in crystalline solids and any books that describe maxwell equations in solids well. I'm interested in how to predict index of refraction of materials and the texts are a bit above my head as I haven't really dealt with...
  40. T

    Magnetic Susceptibility VS. Relative Permeability

    What is the difference between the two and what are the applications of them in a magnetic material?
  41. P

    Correlation between Magnetic susceptibility of soil and it's fertility

    Hi everyone I'm about to undertake my final year project and i will be researching and writing on THE EFFFCT OF HEAT ON THE MAGNETIC SUSCEPTIBILITY OF TOPSOIL and how it relates to SOIL FERTILITY.. I really need help on how to go about it and i'll also need links on contemporary...
  42. N

    Electric susceptibility vs relative permitivity

    So for dielectrics, electric susceptibility (χ) is just the relative permittivity of the dielectric (κ) minus one? => χ = κ -1? Why? Doesn't this mean χ is a completely pointless constant? Just a different way to write κ?
  43. S

    4 nonlinear optics problems: susceptibility, polarization

    [Wasn't sure if each problem needed a separate post. Please feel free to edit if needed.] Also \~ and \^ are tilde and hat respectively. 1a. Homework Statement Use perturbation theory to derive the 3rd order nonlinear susceptibility \chi^{(3)}(3w;w,w,w) (problem gives potential energy, etc...
  44. S

    Magnetic Susceptibility of a Solution

    Hi! I'm trying to calculated the magnetic susceptibility of a solution. I am using this table to know what the susceptibility of each substance is. In other words, I want to know how the magnetic susceptibilities of two (or more) substances add up once they are mixed together into a solution. I...
  45. V

    Electric susceptibility of a gas/solid for the same kind of atoms

    Homework Statement For the same kind of atoms, if a solid is formed from a gas, is the susceptibility increased or decreased compared to the gas phase ? Why ? Homework Equations Susceptibility of a gas is given as χ=N/V * α where N/V is average particle density and α is the...
  46. M

    Magnetic Susceptibility experiment using Faraday method

    1. Good day, Using 4-inch pole caps and a Mettler M5 balance, I got all the values required in order to calculate the magnetic susceptibility of several inorganic compounds such as Manganese (IV) oxide (MnO2). I have the change in mass of the tube with the sample of the compound when the...
  47. H

    Doubt regarding definition of magnetic susceptibility

    Intensity of magnetisation(I) is defined as the magnetic moment per unit volume of the material. It represents the extent to which a specimen is magnetised. I=M/V Magnetising force or magnetising intensity(H) is defined as the number of ampere turns flowing round unit length of toroidal...
  48. F

    H-Field in a region with magnetic susceptibility from an infinite line charge

    Homework Statement Pollack, Stump - Electromagnetism. Prob. 9.23 A long straight wire carrying current 1 is parallel to the z axis and passes through the point (a, 0, 0) . The region x > 0 is vacuum, and the region x < 0 is a material with magnetic susceptibility Xm . Show that the...
  49. maverick280857

    Transverse Susceptibility, and doubts about retarded/advanced Green's Functions

    Hi, I have been working through lecture notes of a condensed matter field theory class, and unfortunately I haven't found references for some of the specialized calculations though the way they're done makes them seem common knowledge in the cond-mat community. I have started this thread...
  50. T

    Magnetic susceptibility of ferrofluids

    Are you aware of typical magnetic susceptibility values for ferrofluids? I've had no luck searching for numerical values.