Pressure- and temperature-dependent Raman spectra of Ca2Fe2O5 oxygen defect perovskite

Shuangmeng Zhai; Bo Dai; Weihong Xue; Justin D Rumney; Hu Wang; Sean R Shieh; Xiang Wu

doi:10.1016/j.saa.2022.121436

Pressure- and temperature-dependent Raman spectra of Ca₂Fe₂O₅ oxygen defect perovskite

Spectrochim Acta A Mol Biomol Spectrosc. 2022 Oct 15:279:121436. doi: 10.1016/j.saa.2022.121436. Epub 2022 May 28.

Authors

Shuangmeng Zhai¹, Bo Dai², Weihong Xue³, Justin D Rumney⁴, Hu Wang⁵, Sean R Shieh⁴, Xiang Wu⁵

Affiliations

¹ Key Laboratory of High-temperature and High-pressure Study of the Earth's Interior, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081, China. Electronic address: zhaishuangmeng@mail.gyig.ac.cn.
² Key Laboratory of High-temperature and High-pressure Study of the Earth's Interior, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081, China; University of Chinese Academy of Sciences, Beijing 100049, China.
³ Key Laboratory of High-temperature and High-pressure Study of the Earth's Interior, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081, China.
⁴ Department of Earth Sciences, University of Western Ontario, London N6A 5B7, Canada.
⁵ State Key Laboratory of Geological Processes and Mineral Resources, China University of Geosciences, Wuhan 430074, China.

PMID: 35660149
DOI: 10.1016/j.saa.2022.121436

Abstract

The Raman spectra of Ca₂Fe₂O₅ were investigated up to 21.8 GPa at room temperature and up to 1073 K at ambient pressure, respectively. A phase transition begins around 13.6 GPa and it is reversible after decompression. No temperature-induced phase transition was observed due to the quality of Raman spectra at temperatures above 773 K. The effects of pressure and temperature on the Raman vibration were quantitatively analyzed. All the observed Raman active vibrations of Ca₂Fe₂O₅ show positive linear pressure dependences and negative temperature dependences with different slopes. Combined with previous experimental results, the isothermal and isobaric mode Grüneisen parameters of Ca₂Fe₂O₅ were estimated, and the intrinsic anharmonicity was discussed.

Keywords: Ca(2)Fe(2)O(5); High pressure; High temperature; Phase transition; Raman spectra.