Magetic Properties of Cl<SUB>b</SUB>-Type Mn Base Compounds

Abstract

The relations of neighboring Mn atoms, Mn–Mn interatomic distances and valence electron numbers to their magnetic moments and magnetic transformation temperatures in Clb-type Mn base compounds have been investigated.The magnetic interaction of these Clb-type compounds is probably dependent upon the type of neighboring Mn atoms. The variation of the Mn–Mn distance of stoichiometric Clb-type compounds is found to be closely related to the change in the Curie temperature rather than the saturation magnetic moment per Mn atom. For many Clb- and L21-type compounds, the relation between the number of valence electron per atom and the ferromagnetic and paramagnetic Curie temperatures are represented by a characteristic curve. The Curie temperatures of Clb-type compounds NiMnSb, PtMnSb and PdMnSb in equivalence per chemical formula decreased gradually with increasing Mn–Mn interatomic distance. With increasing Mn–Mn interatomic distance, the paramagnetic Curie temperatures of CuMnSb, PdMnTe and AuMnSb which have one valence electron higher than the aforementioned compounds increased gradually and the transition from antiferromagnetism to weakly ferromagnetism takes place.