An EPR study of interlayer exchange coupling in the quasi-two-dimensional salts, (CnH2n+1NH3)2CuCl4, with n = 1, 2, and 3

Publisher Website
Google Scholar
Abstract
The interlayer exchange coupling, J′, between magnetically inequivalent ions in adjacent layers has been studied by EPR in the quasi‐two‐dimensional salts of (CnH2n+1NH3)2CuCl4 where n = 1,2,3. The Cu2+ ions of the CuCl42− complexes in adjacent layers of these salts have slightly different g tensor orientations and, in the absence of J′, should give two separate EPR lines when the field does not lie in one of the crystallographic planes of symmetry. The interlayer coupling merges the lines so that a single line is observed whose linewidth becomes broadened at higher frequency. In (C3H2NH3)2CuCl4, J′ is small enough that the individual lines are resolved at 36 GHz. Assuming the g‐tensor orientations are the same in each salt, this allows the ratio ‖J′/J‖ to be deduced from linewidth measurements at 9 and 36 GHz. The ratios are in good agreement with the results obtained from previous magnetic measurements [L. J. de Jongh and A. R. Miedema, Adv. Phys. 23, 1 (1979)].