抄録
Successive structural phase transitions with ferroelectricity were found in TlCoCl3 through dielectric constant measurements and D–E hysteresis loop observations. The sequence of the transitions is identical with that in RbMnBr3 and TlFeCl3, which undergo successive transitions from the prototype crystal structure of CsNiCl3. The temperature dependence of the magnetic susceptibility below TN1 indicates the presence of successive magnetic orderings, which has not been observed in the Ising-like antiferromagnets CsCoCl3 and CsCoBr3 without structural transitions. Dielectric dispersion attributable to the Ising-spin dynamics on a linear-chain spin system was observed at low temperatures. Several problems to be solved are proposed for understanding structural and magnetic properties of TlCoCl3.
