Interchain exchange in nearly one-dimensional Cu(NH3)4PtCl4

Abstract

An interchain exchange $J^{\prime }=500\mathrm{}\pm 100$ G is found in Cu${\left(\mathrm{N}{\mathrm{H}}_3\right)}_4$Pt${\mathrm{Cl}}_4$, a nearly one-dimensional crystal with intrachain exchange $J=5200\mathrm{}$ G along the...CuPtCuPt... stack of square-planar complexes, by combining EPR measurements of $\omega =0\mathrm{}$ Fourier components of high-temperature spin correlation functions with numerical results for purely one-dimensional systems. $J^{\prime }$ is obtained from approximate theories of three-dimensional cutoffs to the slow $t^{\frac{-1\mathrm{}}{2}}$ decay of one-dimensional spin correlations. The method is generally applicable to nearly one-dimensional crystals in which the angular and frequency dependence of the EPR linewidth yields high-temperature Fourier components of spin correlation functions.