Oblique triangular antiferromagnetic phase in CsCu${}_{1-x}$Co${}_x$Cl${}_3$

Abstract

The spin-1/2 stacked triangular antiferromagnet CsCu${}_{1-x}$Co${}_x$Cl${}_3$ with $0.015<x<0.032$ undergoes two phase transitions at zero field. The low-temperature phase is produced by the small amount of Co${}^{2+}$ 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 $x\approx 0.03$. It is found that the intermediate phase is identical to the ordered phase of CsCuCl${}_3$, 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${}^{\circ }$ at $T=1.6$ K decreases with increasing temperature, and becomes zero at $T_{N2}=7.2$ K. An off-diagonal exchange term is proposed as the origin of the oblique phase.

6 pages, 7 figures

References in corpus (1)

• Spin-ordering in S = 1 anisotropic Heisenberg models with nondiagonal spin exchange

Cited by in corpus (1)

• Pressure-Induced Successive Magnetic Phase Transitions in the Spin Gap System TlCuCl${}_3$