The structural phase transition and dehydration for gypsum were investigated by Raman spectroscopy and electrical conductivity up to similar to 12.2 GPa and similar to 723 K. A similar to 5.8 GPa of phase transition was verified at atmospheric temperature. The variations in the sulfate and hydroxyl Raman shifts and a change in electrical conductivity marked the onset of dehydration. At similar to 2.5 GPa, gypsum transformed into bassanite at similar to 523 K, and then completely dehydrated to c-anhydrite at similar to 673 K. And furthermore, the gypsumbassanite and bassanite-anhydrite dehydration boundaries were obtained: P (GPa) = -23.708 + 0.050 T (K) and P (GPa) = -4.907 + 0.011 T (K), respectively. (C) 2018 Elsevier B.V. All rights reserved. Publication name | CHEMICAL PHYSICS LETTERS, 706 151-157; 10.1016/j.cplett.2018.06.007 AUG 16 2018 | Author(s) | Yang, Linfei; Dai, Lidong; Li, Heping; Hu, Haiying; Zhuang, Yukai; Liu, Kaixiang; Pu, Chang; Hong, Meiling | Corresponding author(s) | DAI Lidong dailidong@vip.gyig.ac.cn Chinese Acad Sci, Inst Geochem, Key Lab High Temp & High Pressure Study Earths In, Guiyang 550081, Guizhou, Peoples R China. | View here for the details
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