Accurate Measurements and Determination of the Magnetic Anisotropies of Several Manganese Crystals

Abstract

Magnetic anisotropies of several mangane secrystals have been measured accurately between 77 K and 300 K by using a high sensitive torque-meter. As is predicted by the high temperature expansion theory, the observed magnetic anisotropies vary as the inverse square of the temperature. The crystal field splitting parameters D and E have been obtained for each pure magnetically dense sample. In compounds having the octahedron with two water molecules along the axial direction, the splitting parameters D have been found to be about —0.1 cm-1, which value is two times or one order of magnitude larger than the typical value of Mn2+ surrounded by a distorted octahedron composed of six similar ligands. Especially, the value |D| =0.368 cm-1 for [(CH3)3NH]MnBr32H2O is the largest one reported to date. © 1980, THE PHYSICAL SOCIETY OF JAPAN. All rights reserved.