Raman spectroscopy of quantum paraelectric SrTiO3 fine particles

Size effects of quantum paraelectric SrTiO 3 particles were studied by Raman scattering. The particles were synthesized by a sol-gel method. The particle sizes were controlled by the firing temperatures and determined by the X-ray analysis to range from 12 to 44 nm in diameter. The soft mode frequencies of the smaller particles were higher than those of the larger particles in the low temperature. The soft mode behavior was conforming with dielectric results of the Lyddane-Sachs-Teller relation.