Short Range Order Effect on the Magnetic Anisotropy in a Heisenberg Linear Chain Antiferromagnet CsMnCl₃2H₂O

Abstract

Torque measurements were done for CsMnCl 3 2H 2 O in order to investigate the short range order effect on the magnetic anisotropy in a Heisenberg linear chain antiferromagnet. Above 10 K, the anisotropy in the paramagnetic susceptibility has a uniaxial symmetry referred to the direction of chains ( a -axis) corresponding to the essential intrachain spin correlations and, below this temperature, it becomes orthorhombic because of the evolution of three-dimensional magnetic correlations. The magnitude and temperature dependence of the axial anisotropy observed above 10 K could be explained by the classical linear chain model including only a small dipolar term as an anisotropy term.