Effect of temperature-dependent shape anisotropy on coercivity with aligned Stoner-Wohlfarth soft ferromagnets - Condensed Matter > Materials ScienceReportar como inadecuado




Effect of temperature-dependent shape anisotropy on coercivity with aligned Stoner-Wohlfarth soft ferromagnets - Condensed Matter > Materials Science - Descarga este documento en PDF. Documentación en PDF para descargar gratis. Disponible también para leer online.

Abstract: The temperature variation effect of shape anisotropy on the coercivity,HC(T), for the aligned Stoner-Wohlfarth (SW) soft ferromagnets, such as fcc Ni,fcc Co and bcc Fe, are investigated within the framework of Neel-Brown (N-B)analysis. An extended N-B equation is thus proposed,by introducing a singledimensionless correction function, the reduced magnetization, m(\tao) =MS(T)-MS(0), in which \tao = T-TC is the reduced temperature, MS(T) is thesaturation magnetization, and TC is the Curie temperature. The factor, m(\tao),accounts for the temperature-dependent effect of the shape anisotropy. Theconstants, H0 and E0, are for the switching field at zero temperature and thepotential barrier at zero field, respectively. According to this newly derivedequation, the blocking temperature above which the properties ofsuperparamagnetism show up is described by the expression, TB =E0m^2(\tao)-kBln(t-t0), with the extra correction factor m^2(\tao). Thepossible effect on HC(T) and the blocking temperature, TB, attributed to thedownshift of TC resulting from the finite size effect has been discussed also.



Autor: Lin He, Chinping Chen

Fuente: https://arxiv.org/







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