Frequency dependence of electric susceptibility in the magnetic phase transitions of hexagonal ABX(3)-type antiferromagnets

The temperature dependence of dynamic dielectric constants was measured at several frequencies below 1 MHz for the Ising-type antiferromagnets CsCoBr3 and RbCoBr3. It was found that CsCoBr3 has a dielectric dispersion of an a ctivation type attributable to the dynamics of the propagating domain walls of Ising spins and that RbCoBr3 shows large dielectric anomalies due to th e onset and development of the magnetic ordering through spin-lattice inter actions. (C) 2001 Elsevier Science B.V. All rights reserved.