A new approach to the analysis of magnetisation measurements in rare-earth/transition-metal compounds: application to Nd2Fe14B

Abstract

A new method for the determination of crystal field and exchange parameters in rare-earth/transition-metal compounds, involving the analysis of magnetisation curves, is described. Rather than trying to reproduce directly the magnetisation curves by computer diagonalisation using crystal field and exchange parameters, the method uses experimentally determined anisotropy constants. These constants are parameters which reproduce the magnetisation curves but to which no special physical significance is attached. The energy expansion in terms of these anisotropy constants allows one to avoid long iterative computing. Application of this method to Nd₂Fe₁₄B results in an excellent description of the complex magnetic behavior of this compound.