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Introduction

  • M. S. Sodha
  • N. C. Srivastava

Abstract

All materials interact with externally applied magnetic fields. When the constituents (atoms, molecules, or ions) of a material do not possess a permanent magnetic dipole moment, the interaction of the material with the magnetic field is rather weak and a sample of such a material is repelled from the regions of high magnetic field (diamagnetic behavior). On the other hand, if the constituents of the material do possess a permanent magnetic dipole moment (which may arise from the spin and orbital motion of electrons), it is attracted toward the regions of high magnetic field because the magnetic dipoles have a tendency to align themselves along the direction of the biasing field (paramagnetic behavior). Some of the paramagnetic crystalline solids, when cooled below certain critical temperatures, exhibit magnetic order*; even in the absence of an external magnetic field; this leads to spontaneous magnetization. The magnetic ordering takes place on account of exchange interaction, which has a quantum mechanical origin, discussed at length by Anderson (1963a, b). As a consequence of the exchange interaction, the successive magnetic dipoles are generally aligned either parallel (ferromagnetic behavior) or antiparallel. In the latter case, the magnetic lattice can be looked upon as comprising a number of sublattices, each of which consists of identical magnetic dipoles oriented along a specific crystallographic direction. The net magnetization of the crystal is thus the vector sum of the magnetizations of different sublattices; this may be zero (antiferromagnetic behavior) or finite (ferrimagnetic behavior). The critical temperature at which the transition from the paramagnetic state to the magnetically ordered state is observed is called the Curie temperature for ferromagnetic materials and the Néel temperature for antiferromagnetic and ferrimagnetic materials.

Keywords

Magnetic Dipole Internal Field Anisotropy Field Magnetic Dipole Moment Permeability Tensor 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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References

  1. Akhiezer, A.I., Bar’yakhtar, V.G., and Peletminskii, S.V., 1968, Spin Waves, North-Holland Publishing Co., Amsterdam.Google Scholar
  2. Anderson, P.W., 1963a, in: Solid State Physics, Vol. 14 ( F. Seitz and D. Turnbull, eds.), Academic Press, New York.Google Scholar
  3. Anderson, P.W., 19636, in: Magnetism, Vol. I (G.T. Rado and H. Suhl, eds.), Academic Press, New York.Google Scholar
  4. Artmann, J.O., 1956, Microwave resonance relations in anisotropic single crystal ferrites, Proc. IRE, 44, 1284.CrossRefGoogle Scholar
  5. Auld. B.A., 1965, Geometrical optics of magnetostatic wave propagation in a uniform magnetic field, Bell Syst. Tech. J., 44, 495.Google Scholar
  6. Auld, B.A., 1968, in: Advances in Microwaves, Vol. 3 ( L. Young, ed.), Academic Press, New York.Google Scholar
  7. Bady, I., 1961, Ferrites with planar anisotropy at microwave frequencies, IRE Trans. Microwave Theory Tech, MTT-9, 52.Google Scholar
  8. Berk, A.D., and Lengyel, B.A., 1955, Magnetic fields in small ferrite bodies with application to microwave cavities containing such bodies, Proc. IRE, 43, 1587.CrossRefGoogle Scholar
  9. Berlincourt, D.A., Curran, D.R., and Jaffa, H., 1964, in: Physical Acoustics, Vol. IA (W.P. Mason, ed.), Academic Press, New York.Google Scholar
  10. Brown, W.F., Jr., 1965, Theory of magnetoelastic effects in ferromagnetism, J. Appl. Phys, 36, 994.CrossRefGoogle Scholar
  11. Darby, M.I., and Issac, E.D., 1974, Magnetocrystalline anisotropy of ferro-and ferrimagnetic materials, IEEE Trans. Magnt, MAC-10, 259.Google Scholar
  12. Feynman, R.P., 1972, Statistical Mechanics, W.A. Benjamin, Inc., Reading, Mass.Google Scholar
  13. Gardiol, F.E., 1967, On the thermodynamic paradox in ferrite loaded waveguides, Proc. IEEE, 55, 1616.CrossRefGoogle Scholar
  14. Gardiol, F.E., 1972, Evaluate ferrite tensor components fast, Microwaves (May Issue), 52Google Scholar
  15. Gilbert, T.A., 1955, Armour Research Foundation Rept. No. 11, ARF, Chicago, Ill., unpublished.Google Scholar
  16. Haas, C.W., and Callen, H.B., 1963, in: Magnetism, Vol. I ( G.T. Rado and H. Suhl, eds.), Academic Press, New York.Google Scholar
  17. Helszajn, J., and McStay, J., 1969, External permeability tensor of magnetised ferrite ellipsoid in terms of uniform mode ellipticity, Proc. IEEE, 116, 2088.Google Scholar
  18. Joseph, R.I., 1966, Ballistic demagnetizing factors in uniformly magnetised cylinder, J. Appl. Phys, 37, 4639.CrossRefGoogle Scholar
  19. Joseph, R.I., 1967, Ballistic demagnetizing factors in a uniformly magnetized rectangular prism, J. Appl. Phys, 38, 2405.CrossRefGoogle Scholar
  20. Joseph, R.I., and Schlömann, E., 1965, Demagnetizing fields in non-ellipsoidal bodies, J. Appl. Phys, 36, 1579.CrossRefGoogle Scholar
  21. Kanamori, J., 1963, in: Magnetism, Vol. I ( G.T. Rado and H. Suhl, eds.), Academic Press, New York.Google Scholar
  22. Kittel, C., 1947, Interpretation of anomalous Larmor frequencies in ferromagnetic resonance experiment, Phys. Rev, 71, 270.CrossRefGoogle Scholar
  23. Kittel, C., 1948, On the theory of ferromagnetic resonance absorption, Phys. Rev, 73, 155.CrossRefGoogle Scholar
  24. Kittel, C., 1971, Introduction to Solid State Physics, 4th edition, John Wiley and Sons, Inc., New York.Google Scholar
  25. Landau, L.D., and Lifshitz, E.M., 1935, On the theory of dispersion of magnetic permeability in ferrimagnetic bodies, Phys. Z. Sowjetunion. (English), 8, 153.Google Scholar
  26. Lax, B., and Button, K.J., 1962, Microwave Ferrites and Ferrimagnetics, McGraw-Hill Book Co., New York.Google Scholar
  27. Lewandowsky, S.J., 1964, Ferrite ellipsoid in parallel field, Br. J. Appl. Phys, 15, 193.CrossRefGoogle Scholar
  28. Osborne, J.A., 1945, Demagnetizing factors of the general ellipsoid, Phys. Rev, 67, 351.CrossRefGoogle Scholar
  29. Polder, D., 1949, On the theory of ferromagnetic resonance, Philos. Mag, 40, 99.zbMATHGoogle Scholar
  30. Schiff, L.I., 1968, Quantum Mechanics,.3rd edition, McGraw-Hill Book Co., New YorkGoogle Scholar
  31. Schlömann, E., 1970, Demagnetizing fields in thin magnetic films due to surface roughness, J. Appl. Phys, 41, 1617.CrossRefGoogle Scholar
  32. Schneider, B., 1972, Effect of magnetocrystalline anisotropy on magnetostatic spin wave modes in plates I: Theoretical results for infinite plates, Phys. Status Solidi, (b)51, 325.Google Scholar
  33. Smit, J., and Wijn, H.P.J., 1959, Ferrites, John Wiley and Sons, Inc., New York.Google Scholar
  34. Sommerfeld, A., 1952, Electrodynamics, Academic Press, New York.zbMATHGoogle Scholar
  35. Sparks, M., 1964, Ferromagnetic Relaxation Theory, McGraw-Hill Book Co., New York.Google Scholar
  36. Stratton, J., 1941, Electromagnetic Theory, McGraw-Hill Book. Co., New York.Google Scholar
  37. Suhl, H., 1955, Ferromagnetic resonance in nickel ferrite between one and two kilomegacycles, Phys. Rev, 97, 555.CrossRefGoogle Scholar
  38. Tiersten, H.F., 1964, Coupled magnetomechanical equations for magnetically saturated insulators, J. Math. Phys, 5, 1298.MathSciNetzbMATHCrossRefGoogle Scholar
  39. Vittoria, C., Bailey, G.C., Barker, R.C., and Yelon, A., 1973, Ferromagnetic resonance field and linewidth in an anisotropic magnetic metallic medium, Phys. Rev, B7, 2112.Google Scholar
  40. Vittoria, C., Craig, J.N., and Bailey, G.C., 1974, General dispersion law in a ferrimagnetic cubic magnetoelastic conductor, Phys. Rev, B10, 3945.Google Scholar
  41. von Aulock, W.H., 1965, Handbook of Microwave Ferrite Materials, Academic Press, New York.Google Scholar
  42. von Aulock, W.H., and Rowan, J.H., 1957, Measurement of dielectric and magnetic properties of ferromagnetic materials at microwave frequencies, Bell. Syst. Tech. J, 36, 427.Google Scholar
  43. Wagner, D., 1972, Introduction to the Theory of Magnetism, Pergamon Press, Oxford. Waldron, R.A., 1957, Theory of measurements of the permeability tensor of a ferrite by means of a resonance cavity, Proc. Inst. Electr. Eng, 104B, 307.Google Scholar
  44. Waldron, R.A., 1959, Electromagnetic fields in ferrite ellipsoid, Br. J. Appl. Phys, 10, 20.CrossRefGoogle Scholar
  45. White, R.M., 1970, Quantum Theory of Magnetism, McGraw-Hill Book Co., New York.Google Scholar

Copyright information

© Springer Science+Business Media New York 1981

Authors and Affiliations

  • M. S. Sodha
    • 1
  • N. C. Srivastava
    • 1
  1. 1.Indian Institute of TechnologyNew DelhiIndia

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