Effect of Exchange Interaction on the Magnetic and Thermal Properties of Copper Salts and Copper Coordination Compounds

Abstract

This paper has two purposes. The first is to derive general formulas for the specific heat and the susceptibility of a compound in which there are two magnetically inequivalent ions with effective spin ½ in each unit cell. Dipole-dipole and anisotropic exchange interactions are taken into account in the derivations. The second purpose is to explore in a rather tentative way the possibility of applying the theory to a compound in which the magnetic ions are strongly coordinated to the surrounding anions. The compound selected for detailed study is copper tetrammine sulfate monohydrate. Experimental data on this compound are neither as extensive nor as accurate as one might wish, and the theory contains a large number of adjustable parameters. Consequently it is impossible to make sharp judgments about the values of the parameters. It is concluded, however, that exchange interactions have important effects on the magnetic and thermal properties of copper tetrammine sulfate. Other substances to which the theory might be applied are mentioned.