PHASE-TRANSITION IN PB4.8CA0.2GE3O11 FERROELECTRICS

Polycrystalline samples of calcium-doped lead germanate Pb4.8Ca0.2Ge3O 11 were prepared by a solid-state reaction technique. Preliminary X-ra y studies have been carried out to check the formation of the single p hase and to determine its basic crystal structure, Measurements of die lectric permittivity (epsilon) and dielectric loss (tan delta) as a fu nction of temperature (from room temperature to 180 degrees C) at 1 kH z and 10 kHz have shown a dielectric anomaly acid a phase transition a t about 80 +/- 2 degrees C.