Magnetic Structure, Magnetization, and Short-Range Spin Correlations in the Ising Linear-Chain Antiferromagnet CsCoCl3·2H2O

Abstract

The magnetic space group and structure of CsCo${\mathrm{Cl}}_3$ · 2${\mathrm{H}}_2$O have been confirmed. From the intensity of the Bragg scattering the magnetization-vs-temperature curve has been determined. It agrees closely with that obtained from NMR work and follows the power law $\frac{M\left(T\right)\mathrm{}}{M\left(0\right)\mathrm{}}=2.34\mathrm{}{(1-\frac{T}{T_N})}^{0.44}$ in the range $3.20\le T<\mathrm{}{T}_N=3.40\mathrm{}$ K. Intrachain and interchain spin-correlation lengths have been determined. Between $T_N$ and 4.2 K, the intrachain correlation remains practically constant while the interchain correlation steeply decreases with increasing temperature, thus giving rise to the formation of a linear-chain system. An estimate for the intrachain exchange leads to $25<\left|J_a\right|<\mathrm{}35\mathrm{}$ K.