Ferroelectricity and Dielectric Critical Slowing-Down in LiNaGe4O9 Single Cyrstal

Single crystals of LiNaGe 4 O 9 were grown by the Czochralski technique from stoichiometric melt. It has been found that LiNaGe 4 O 9 shows ferroelectric activity in the a -direction below T c =112.7 K. The spontaneous polarization is about 0.33 µC/cm 2 at 110.3 K. The complex dielectric constants were measuredat 120 Hz, 1 kHz and 10 kHz as functions of temperature. The dielectric dispersion has been found in the above frequency region and explained by the critical slowing-down of the polarization relaxation process.