The spin-1/2 stacked triangular antiferromagnet CsCu1−xCoxCl3 with 0.015<x<0.032 undergoes two phase transitions at zero field. The low-temperature phase is produced by the small amount of Co2+ doping. In order to investigate the magnetic structures of the two ordered phases, the neutron elastic scattering experiments have been carried out for the sample with x≈0.03. It is found that the intermediate phase is identical to the ordered phase of CsCuCl3, and that the low-temperature phase is an oblique triangular antiferromagnetic phase in which the spins form a triangular structure in a plane tilted from the basal plane. The tilting angle which is 42∘ at T=1.6 K decreases with increasing temperature, and becomes zero at TN2=7.2 K. An off-diagonal exchange term is proposed as the origin of the oblique phase.
@article{arxiv.cond-mat/0010385,
title = {Oblique triangular antiferromagnetic phase in CsCu$_{1-x}$Co$_x$Cl$_3$},
author = {T. Ono and T. Kato and H. Tanaka and A. Hoser and N. Stusser and U. Schotte},
journal= {arXiv preprint arXiv:cond-mat/0010385},
year = {2009}
}