We present a rigid-ion model of Ba1-xKxBiO3 for compositions x=0.25 and x=0.40. Partial vibrational density of states of ions in the compounds Ba0.75K0.25BiO3 and Ba0.6K0.4BiO3 are reported at room temperature and 100 K. The oxygen modes dominate the vibrational spectrum from 150 up to 820 cm-1. The low frequency modes are associated with the cations. The number of substituted K around an oxygen favors high frequency vibrational modes. Qualitative agreement between the calculated phonon density of states of Ba0.6K0.4BiO3 and available experimental data is achieved.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Electrical and Electronic Engineering