High-temperature vibrational spectra, relaxation and ionic conductivity effects in KTiOPO4

Autor:	F Brehat, G E Kugel, Patrick Simon, B Mohamadou, G Marnier, B Wyncke
Rok vydání:	1991
Předmět:	Phase transition Chemistry Infrared spectroscopy Atmospheric temperature range Condensed Matter Physics Molecular physics symbols.namesake Nuclear magnetic resonance symbols Relaxation (physics) Ionic conductivity General Materials Science Raman spectroscopy Raman scattering Debye
Zdroj:	Journal of Physics: Condensed Matter. 3:9489-9501
ISSN:	1361-648X 0953-8984
DOI:	10.1088/0953-8984/3/47/021
Popis:	High-temperature Raman and infrared spectra measurements have been performed on KTiOPO4 single crystals in a temperature range from room temperature to 1000 K. Special attention is paid to the low-frequency Raman spectra which exhibit an anomalously large quasi-elastic scattering: this appears with an increase in temperature. The Raman spectra were fitted using a response function involving one oscillator and two Debye relaxations. The resulting parameters are analysed and discussed in order to clarify the phase transition mechanism and, more specifically, the influence of the potassium (K) ion on this transition and on the ionic conductivity. The high-temperature infrared reflectivity spectra were fitted for the two polar mode configurations A1 and B2 and have been analysed critically within the previously-mentioned framework.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::ed48da8b8c081ac16ad645604fba3444 https://doi.org/10.1088/0953-8984/3/47/021 Zobrazit plný text záznamu