Single crystal susceptibility of the S = 1 one-dimensional Heisenberg antiferromagnet AgVP2S6

Abstract

A reliable single crystal susceptibility data is reported to reveal the ground state property of the S = 1 one-dimensional Heisenberg antiferromagnet AgVP2S6. The observed susceptibilities for the parallel and perpendicular direction to the chain axis fall down rapidly as the temperature is lowered down to about 50 K, revealing a non-magnetic singlet ground state nature of the system. The results are interpreted quantitatively within the framework of the Haldane prediction, giving the quantum gap of Eg kB ≈ 250 K which should be compared with 320 K from neutron scattering. © 1994.