Raman Spectroscopic Evaluation and Microwave Dielectric Property of Order/Disorder and Stoichiometric/Non-Stoichiometric Ba(Zn_1/3Ta_{2 /3})O₃

Abstract

The phonon vibrations, crystal phases, lattice defects and Q factors of stoichiometric Ba(Zn_1/3Ta_2/3)O₃ (BZT) and non-stoichiometric BZT were studied. The significant Q factor decrement and the change of the phonon vibration were simultaneously observed in the non-stoichiometric disordered BZT formed in Ba-rich region. The Q factor decrement in the non-stoichiometric disordered BZT can be attributed to the change of A _1g (O) mode. These results suggest that the lattice defects (B site vacancy and oxygen vacancy) formed by excessive Ba should play an important role in the phonon vibration and Q factor of BZT. On the contrary, in the case of the stoichiometric BZT, the ionic vibrations detected by Raman scattering were independent of the crystal-structural ordering and microwave Q factor.

Keywords:

• Dielectric properties
• perovskite
• X-ray methods
• microwave
• Q factor
• ordering
• raman scattering