Effect of Defects of Spin Interactions in a Simple Cubic Lattice

Publisher Website
Google Scholar
Abstract
Effects of lattice defects such as foreign atoms or holes on spin-spin interactions in a simple cubic lattice are calculated by using the so-called spherical model developed by Montroll, Berlin and Kac, and others. In the case when the concentration of defects is low and the distance between any pair of defects is large, the exact positions of the defects are not important and the excess free energy and other thermodynamical functions are determined by the concentration and the nature of defects. The Langevin-Curie law of magnetic susceptibility is modified by the presence of defects. The ferromagnetic Curie point is also affected by the presence of defects and is a linear function of defect concentration for low concentrations. When defect atoms have stronger exchange interactions with their nearest neighbors than that of the rest of the atoms in the lattice, the Curie point is raised and the specific heat vs temperature curve is enhanced. The reverse is true when defect atoms have weaker exchange interactions with their nearest neighbors.

This publication has 13 references indexed in Scilit: