Preparation of Ba_xSr_(l-x)TiO_3 Pyroelectric Ceramics by Sol-Gel Technique

The BaxSr1-xTiO3 (BST) materials of various compositions (x=0.75,0.70,0.60) were preparedby sol-gel processing. The reaction mechanism was investigated by FT-IR technique. The thermolysis process of the BST-gel was analyzed by DTA and XRD. The dependence of Curie pointon compositions and the properties of the IR detection for the BST sample under dc bias werealso studied. The results showed that the synthetic temperature of BST powder is 930℃, which ismuch lower than that by the conventional solid-state reaction method, the BST powder obtainedhas a narrow distribution. The sintering temperature falls from 1380℃ to 1320℃, the overgrowthof the grain is constrained and the average grain size is -5m. The relative permittivity of theBST sample increases by 20% over that by the conventional processing, the minimum dissipationfaCtor measured is 0.0025, and the pyroelectric coefficient reaches at 20x 10(-8)C/cm2.K.