Phase Relations and Pressure-Volume-Temperature Equation of State of Galena

• Published in: Chinese physics letters Vol. 27; no. 8; pp. 151 - 154
• Main Author: 范大伟 周文戈 魏舒怡 刘景 李延春 蒋升 谢鸿森
• Format: Journal Article
• Language: English
• Published: IOP Publishing 01.08.2010
• Subjects: Bulk modulus; Compressibility; Derivatives; Diamond anvil cells; Equations of state; Galena; Synchrotron radiation; Thermal expansion; 体积模量; 压力; 容积; 弹性各向异性; 热膨胀系数; 状态方程; 相位关系; 高温高压
• ISSN: 0256-307X; 1741-3540
• DOI: 10.1088/0256-307X/27/8/086401

The phase relations and pressure volume dependences of galena （PbS） under high pressure and high temperature are investigated by means of in situ observation using resistance heating in a diamond anvil cell and synchrotron radiation. The phase transition from NaCl type to TII type takes place at approximately 2.4 GPa. A fit to the high temperature third-order Bireh-Murnaghan equation of state yields an isothermal bulk modulus Ko = 37（3） GPa, and its pressure derivative K＇0 = 3.6（3）, the temperature derivative of the bulk modulus （ K/ T）p = -0.022（9） GPaK^-1, and the thermal expansion coeffeient α0 = 2.2（5） × 10^-5 K^-1 for TII-type galena. The linear compressibilities j3 along a, b and c directions of TII type is elastically anisotropic （βa = 3.4 × 10^-3 GPa^-1, βb = 1.4× 10^-4 GPa^-1 and βc = 1.6 × 10^-3 GPa^-1）. We obtain the temperature derivative of the bulk modulus （ K/ T）p and thermal expansion coefficient α0 for TlI-type galena for the first time.