Study of cation ordering in Ba(Yb<inf>1/2</inf>Ta<inf>1/2</inf>) O<inf>3</inf> by X-ray diffraction and Raman spectroscopy

The complex perovskite Ba(Yb1/2Ta1/2)O3 has been prepared by the two-stage solid-state reaction method. Rietveld' refinement analysis indicates cubic perovskite phase with space group. The 1:1 cation ordering at the B-site is revealed by the presence of (111) superlattice reflection in the X-ray diffraction pattern and further evidenced by the presence of A1g and F2g vibrational modes in the Raman spectra. The dielectric constant is measured to be 29.1, the product of quality factor and resonant frequency ( Q × f ) is found to be 32,000 GHz and the temperature coefficient of resonant frequency (τf) is 135 (ppm/°C) in the temperature range 30-70°C. © 2008 American Ceramic Society.