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Magnetic Rotation Phenomena in a Polycrystalline Ferrite
Phys. Rev. 97, 60 – Published 1 January, 1955
DOI: https://doi.org/10.1103/PhysRev.97.60
Abstract
In order to calculate the initial susceptibility at high frequencies of a polycrystalline sample of ferrite, one must take account of the interaction between neighboring crystallites, and of the fact that the crystallites differ from each other in their orientation (assumed random) and in their characteristic resonant frequencies. Each crystallite is acted upon by an oblique alternating field, and its magnetization processes in an elliptical cone. A simple solution of this problem is given by the use of complex variables involving two different imaginaries. It is found that the interaction between crystallites has little effect on the magnetic spectrum other than to raise the effective value of the resonant frequencies, and that the spectrum obtained is not very sensitive to the exact form chosen for the distribution of resonant frequencies among the crystallites.
The resulting expressions for the real and imaginary parts of the susceptibility are compared with the results of some measurements by F. Brown and C. L. Gravel on a lightly-sintered sample of nickel ferrite, assuming that the major part of the susceptibility is due to rotation processes. The agreement is satisfactory and shows among other things that the damping constant need be no larger in these materials than it is found to be in a single crystal.
References (24)
- G. T. Rado, Revs. Modern Phys. 25, 81 (1953) H. P. J. Wijn, dissertation, Leyden, 1953 (unpublished)
- F. Brown and C. L. Gravel, Phys. Rev. 95, 652(A) (1954) [ 97, 55 (1954)]
- Philips group [J. Went and H. Wijn, Phys. Rev. 82, 269 (1951)]
- J. L. Snoek, Physica 14, 207 (1948)
- F. Brown and D. Park, Phys. Rev. 93, 381 (1954)
- [H. A. Lorentz, The Theory of Electrons (Dover Publications, Inc., New York, 1952), p. 138 and Note 55]
- L. Landau and E. Lifschitz, Physik. Z. Sowjetunion 8, 153 (1935)
Omitted endnote
- Kittel ([1]) C. Kittel, J. phys. radium 12, 332 (1951)
- N. Bloembergen, Phys. Rev. 78, 572 (1950)
- Yager, Galt, Merritt, and Wood, Phys. Rev. 80, 744 (1950)
- D. W. Healy, Jr., Phys. Rev. 86, 1009 (1952)
- D. Park, Phys. Rev. 95, 962(A) (1954)
Omitted endnote
- J. A. Young, Jr., and E. A. Uehling, Phys. Rev. 94, 544 (1954)
Omitted endnote
Omitted endnote
- D. Polder and J. Smit, Revs. Modern Phys. 25, 89 (1953)
- Rado, Wright, and Emerson, Phys. Rev. 80, 273 (1950)
- F. Brown (private communication)
Omitted endnote
- [6], Note 54
- [G. T. Rado and J. R. Weertman, Phys. Rev. 94, 1411(A) (1954).]
Omitted endnote