High-pressure investigations on the isostructural phase transition and metallization in realgar with diamond anvil cells

• Published in: Di xue qian yuan. Vol. 12; no. 2; pp. 1031 - 1037
• Main Authors: Yang, Linfei, Dai, Lidong, Li, Heping, Hu, Haiying, Hong, Meiling, Zhang, Xinyu, Liu, Pengfei
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier B.V 01.03.2021; Elsevier Science Ltd; University of Chinese Academy of Sciences,Beijing,100049,China%Key Laboratory of High-Temperature and High-Pressure Study of the Earth's Interior,Institute of Geochemistry,Chinese Academy of Sciences,Guiyang,Guizhou,550081,China%State Key Laboratory of Structural Chemistry,Fujian Institute of Research on the Structure of Matter,Chinese Academy of Sciences,Fuzhou,Fujian,350002,China; Key Laboratory of High-Temperature and High-Pressure Study of the Earth's Interior,Institute of Geochemistry,Chinese Academy of Sciences,Guiyang,Guizhou,550081,China; Elsevier
• Subjects: Bulk modulus; Compressibility; Crystals; Diamond anvil cells; Electrical conductivity; Electrical properties; Electrical resistivity; First principles; High pressure; Isostructural phase transition; Mathematical analysis; Metallization; Metallizing; Phase transitions; Raman spectra; Raman spectroscopy; Realgar; Unit cell; Realgar; Metallization; Electrical conductivity; Raman spectroscopy; Isostructural phase transition; High pressure
• ISSN: 1674-9871; 2588-9192
• DOI: 10.1016/j.gsf.2020.05.017

The high-pressure structural, vibrational and electrical properties for realgar were investigated by in-situ Raman scattering and electrical conductivity experiments combined with first-principle calculations up to ~30.8 ​GPa. It was verified that realgar underwent an isostructural phase transition at ~6.3 ​GPa and a metallization at a higher pressure of ~23.5 ​GPa. The isostructural phase transition was well evidenced by the obvious variations of Raman peaks, electrical conductivity, crystal parameters and the As–S bond length. The phase transition of metallization was in closely associated with the closure of bandgap rather than caused by the structural phase transition. And furthermore, the metallic realgar exhibited a relatively low compressibility with the unit cell volume V0 ​= ​718.1.4 ​Å3 and bulk modulus B0 ​= ​36.1 ​GPa. [Display omitted] •The structural, vibrational and electrical properties of realgar are studied up to ~30.8 ​GPa.•A ~6.3 ​GPa of isostructural phase transitionin realgar is well verified.•The realgar undergoes a ~23.5 ​GPa of metallization phase transition.•The metallization is in closely related to the closure of band gap.