Low Temperature Dielectric Properties of (Rb_1-xK_x)₂ZnI₄Mixed Crystals

Abstract

Rb2ZnI4 shows phase transitional anomalies at about 4 K and about 62 K in the temperature dependence of the dielectric constant. To investigate those, the mixed systems (Rb1-xKx)2ZnI4 and Rb2Zn1-xCdxI4 were prepared by both evaporation from the aqueous solution and Czochralski method from the melt. Dielectric constant, spontaneous polarization and thermal expansion measurements were performed for such mixed systems. For (Rb1-xKx)2ZnI4, the phase diagram was completed over full range of concentration x.