Low-temperature magnetic properties of [(C2H5)2NH2]CuCl4, a two-dimensional magnetic system

The static magnetic susceptibility and EPR spectra of the low temperature phase of [(C2H5)2NH2]2CuCl4 have been measured. The susceptibility is indicative of a low-dimensional antiferromagnet, and on the basis of structural characteristics, has been interpreted as a two-dimensional system. Analysis of the susceptibility in terms of the high temperature series expansion for the two-dimensional Heisenberg system gave an excellent fit to the data with ‖J‖/k =1.87 K. The EPR data confirmed the presence of exchange coupling. The narrow EPR linewidths (3–6 Oe) are explained on this basis. The angular variation is shown to arise from g tensor anisotropy as well as anisotropic and antisymmetric exchange terms.