Dilatometric Study of Ferroelectric Rb_2CdI_4 Monoclinic Crystal Grown by Czochralski Method

摘要

Crystal growth of Rb_2CdI_4 was performed by Czochralski method. Transparent colourless crystals with monoclinic structure were obtained. Temperature dependence of the dielectric constant along the b-axis was measured with variation of frequency. The thermal expansions x, (i = a, b, c and a' ; a' = a + c) along the four independent axes were measured both by clip-type strain-gauge dilatometer and X-ray diffraction methods. These results show distinct anomalies associated with the ferroelectric transition at T_C = 210 K.