Differential susceptibility measurements were made on a single crystal of the antiferromagnet [(${\mathrm{CH}}_3$${)}_3$NH]${\mathrm{Co}}_{0.4}$${\mathrm{Ni}}_{0.6}$${\mathrm{Cl}}_3$⋅${2\mathrm{H}}_2$O in the temperature range 2.5 K≤T≤6 K. The complex susceptibility at various frequencies was analyzed with the Cole-Cole phenomenological model. Below the Néel temperature, $T_N$=4.35 K, from 3 K to 4.2 K, the zero-frequency isothermal susceptibility was found to be ${\chi }_0$=260 emu/mole, and the width of the distribution of relaxation times to be α=0.24±0.03 where α=0 corresponds to a single relaxation time and α=1 to an infinitely wide distribution. Coexistence of spin-glass, ferromagnetic, and antiferromagnetic order is discussed.

• Received 25 May 1989

DOI:https://doi.org/10.1103/PhysRevB.40.9431