The Cluster Approach with Effective Field Approximation to Exchange Coupling in Layer-Type Compound Cu(NH₃)₂CO₃

Abstract

Magnetic susceptibility data on Cu(NH₃)₂CO₃ are analyzed by the effective field approximation in addition to a cluster approach. The layer structure of Cu(NH₃)₂CO₃ consists of carbonate bridged chains of copper (II) ions linked together into sheets by hydrogen bonding. The cluster model of three copper ions under the effective fields gives a nice fit with the experimental data with the intrachain exchange constant of −5.9 K and the interchain exchange constant of 5.5 K. The results are compared with those of the recent investigation by the cluster approach.