Magnetic and Magneto-Optical Properties of Sn-Substituted Mn2Sb Films

Following our previous study on vacuum-evaporated Mn2Sb films with bismuth and chromium added, we have investigated the magnetic and magnetooptic properties of tin-substituted Mn2Sb (Mn2Sb1-xSnx) films, with x varied from 0 to about 0.40 (13.2 at% Sn). Tin was chosen as the third element because there are two magnetic intermetallic compounds with different crystallographic structures in this system--Mn2Sb has a tetragonal structure, while Mn2Sn has a hexagonal structure. As the amount of tin substitution increases, the diffraction lines from Mn2Sb become weak and the saturation magnetization decreases, but perpendicular magnetization films can nonetheless be obtained up to x=0.40. Results show that shrinking along the c-axis of the Mn≪≪MDSD≫≫2≪≪MDNM≫≫Sb lattice occurs in the vicinity of x=0.15 (5 at% Sn), at which a decrease in coercivity and increase in polar Kerr rotation are observed. These are considered to be closely related phenomena, presumably reflecting a change in the electronic structure of Mn2Sb.