NANO-SIZE EFFECTS ON THE QUANTUM PARAELECTRIC SRTIO3 FINE PARTICLES

Nano-size effects on the dielectric and soft mode behaviors in the qua ntum paraelectric SrTiO3 were studied. Nanocrystalline SrTiO3 particle s were prepared by the sol-gel method, and the particle sizes were con trolled by treating temperatures. The sizes were determined to be from 12 to 44 nm using Scherrer's formula. The transition temperatures fro m classical paraelectric to quantum paraelectric phase were increased for the smaller sizes of the particles. Soft mode behaviors of fine pa rticles were investigated by Raman scattering. The soft mode frequenci es of the smaller sizes of the particles were higher than those of the larger ones in the low temperature. The soft mode behaviors were agre ed with dielectric results through the Lyddane-Sachs-Teller relation.