Temperature Dependence of Anisotropy Energy of Mn₂Sb

Theoretical studies on the microscopic origin of the magnetic anisotropy energy of Mn 2 Sb and its temperature dependence are reported. As has been observed by Jarrett et al , it is well expressed by E α = K 1 sin 2 θ. K 1 may be expressed as K 1 = K 1 dip + K 1 cry ; K 1 dip is the anisotropy constant coming from the magnetic dipolar interaction and its value at absolute zero is calculated by the Ewald-Kornfeld method to be -2.99×10 6 erg per c.c., or -0.411 cm -1 per atom; K 1 cry comes from the single ion spin energy, which is assumed to be of the form, D S z 2 . Calculation of the temperature dependence of K 1 dip and K 1 cry based on the molecular field approximation. D -parameters, D I and D II , of the two kinds of manganese atoms on magnetically non-equivalent sites are determined to be -6.16 cm -1 per atom and 0.977 cm -1 per atom, respectively, by fitting the calculated K 1 to the experimental one.