Dielectric and phase transitional properties of Rb 2 ZnI 4 and its mixed systems at low temperatures

The temperature dependence of the dielectric constant of Rb 2 ZnI 4 shows two peak anomalies: one at 4 K and the other at 62 K. To study this, we prepared crystals of the mixed system Rb 2 Zn 1- x Cd x I 4 from the melt by using the Czochralski method. Dielectric constant and spontaneous polarization measurements were performed on crystals from the mixed system. The phase diagram of Rb 2 Zn 1- x Cd x I 4 was completed over a full range of concentrations x. The result was compared with the already-reported result for (Rb 1- x K x ) 2 ZnI 4 .