Ferromagnetism, Antiferromagnetism, and Ferrimagnetism
In ferromagnetic materials the magnetization versus magnetic field relationship exhibits hysteresis similar to that encountered in Chapter 8 for the relationship between P and E in ferroelectric materials. Of the elements, only Fe, Ni, Co, Gd, and Dy are ferromagnetic, although there are a relatively large number of ferromagnetic alloys and oxides (see Table 19-2). Above a critical temperature θ, known as the ferromagnetic Curie temperature the spontaneous magnetization vanishes and the material becomes paramagnetic. Well above the Curie temperature the susceptibility follows the Curie-Weiss lawwhere θ is the Curie constant; the temperature 6 is called the paramagnetic Curie temperature and is usually some degrees higher than θf(see Fig. 19-4).
Unable to display preview. Download preview PDF.
- L. F. Bates, Modern Magnetism, 3d ed., Cambridge, London, 1951.Google Scholar
- R. M. Bozorth, Ferromagnetism, Van Nostrand, New York, 1951.Google Scholar
- J. L. Snoek, New Developments in Ferromagnetic Materials, Elsevier, New York, 1947.Google Scholar
- E. C. Stoner, “Ferromagnetism,” Repts. Progr. Phys., 11, 43 (1948); 13, 83 (1950).Google Scholar
- Report on Washington Conference on Magnetism, Revs. Mod. Phys. January 1953.Google Scholar
- Report on Grenoble Conference on Magnetism, J. phys. rad. March 1951.Google Scholar
© Macmillan Publishers Limited 1981