Temperature dependence of soft mode frequency and width in potassium and sodium niobate

Authors
Lingwal, V Singh, K Bhatt, SC Panwar, NS Semval, BS
Citation
V. Lingwal et al., Temperature dependence of soft mode frequency and width in potassium and sodium niobate, I J PA PHYS, 38(7), 2000, pp. 533-535
Citations number
14
Categorie Soggetti
Physics
Journal title
INDIAN JOURNAL OF PURE & APPLIED PHYSICS
ISSN journal
00195596 → ACNP
Volume
38
Issue
7
Year of publication
2000
Pages
533 - 535
Database
ISI
SICI code
0019-5596(200007)38:7<533:TDOSMF>2.0.ZU;2-A
Abstract
Considering a quartic anharmonic model Hamiltonian and using Green's functi on and Dyson's equation technique, expressions for soft mode width and freq uency in perovskite type crystals have been obtained. Using the experimenta lly observed dielectric and loss behaviour of potassium and sodium niobate crystals the temperature dependence of soft mode width and frequency in the se crystals have been calculated. Anomaly has been observed in the behaviou r of soft mode frequency and width, near the transition temperatures in the se compounds.