The ground state of the stacked triangular antiferromagnet CsFeBr3 is a spin singlet due to the large single ion anisotropy D(Sz)2. The field-induced magnetic ordering in this compound was investigated by the magnetic susceptibility, the magnetization process and specific heat measurements for an external field parallel to the c-axis. Unexpectedly, two phase transitions were observed in the magnetic field H higher than 3 T. The phase diagram for temperature versus magnetic field was obtained. The mechanism leading to the successive phase transitions is discussed.
@article{arxiv.cond-mat/0104287,
title = {Field-Induced Two-Step Phase Transitions in the Singlet Ground State Triangular Antiferromagnet CsFeBr$_3$},
author = {Y. Tanaka and H. Tanaka and T. Ono and A. Oosawa and K. Morishita and K. Iio and T. Kato and H. Aruga Katori and M. Bartashevich and T. Goto},
journal= {arXiv preprint arXiv:cond-mat/0104287},
year = {2009}
}