The Effect of sintering process on Electrical and Microstructural propertiesof Barium-Strontium-Titanate

Effect of sintering parameters on the microstructure of the Ba۰.۵Sr۰.۵TiO۳ ceramics wasinvestigated. BST green compacts were sintered at various temperatures ranging from ۱۲۵۰to ۱۴۰۰ ºC in air for time periods varying from ۱ hour to ۲ hours. A dielectric sputteringtarget comprising BST sintered body having a high density, purity and a fine-grainedmicrostructure has been also fabricated. Optimized sintering condition was obtained bycontrolling sintering temperature and time to fabricate single phase, high relative densitysintered body. A relative density of up to ۹۲% and mean grain size of below ۱۰ μm werereached at the sintering temperature of ۱۳۰۰ ºC. However the maximum density of thesamples was related to the sample sintered at ۱۴۰۰ °C, but in this condition the mean grainsize of the samples was larger than ۵۰μm which is not desirable for sputtering. The preparedtarget has been used in a laboratory made sputtering system to deposit thin film of BST onMo coated soda lime glass. The dielectric constants of the BST thin films have beencalculated from measured value of capacitance of fabricated MIM capacitors in variousfrequencies ranging from ۱۰KHz to ۱MHz. The dielectric constant of thin films at ۱۰ KHzwas around ۴۰۰۰. Characteristics of the body were analyzed by X-ray diffraction (XRD),and optical microscopy

Keywords:

Barium Strontium Titanate , Sputtering Target , High Dielectric Material