Spin-wave analysis of pseudo-one-dimensional antiferromagnet CsMnCl3·2H2O

Abstract

The low-temperature specific heat, sublattice magnetization, zero-point spin reduction, and ground-state energy of CsMn${\mathrm{Cl}}_{3}$\ifmmode\cdot\else\textperiodcentered\fi{}${2\mathrm{H}}_{2}$O have been confronted with a spin-wave calculation, which was based upon the particular magnetic structure of this compound. In this numerical calculation the effect of small interchain interactions and a temperature-dependent anisotropy gap have been included. A good agreement with the experimental heat capacity was obtained for an intrachain interaction $\frac{J}{k}=\ensuremath{-}3.0$ K and a ratio of the inter-to intrachain interaction $|\frac{{J}^{\ensuremath{'}}}{J}|=8\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}3}$. These values compare favorably with the results from other studies. The predicted sublattice magnetization, including the zero-point spin reduction of 19%, is in good agreement with the experimental evidence. The calculated ground-state energy corresponds with the value obtained by direct integration of the experimental magnetic heat capacity. It was concluded that unrenormalized spin-wave theory offers a fair description of the magnetic behavior of CsMn${\mathrm{Cl}}_{3}$\ifmmode\cdot\else\textperiodcentered\fi{}${2\mathrm{H}}_{2}$O up to $\ensuremath{\sim}0.6{T}_{N}$.