Pressure-induced phase transitions in CaB₆ by means of XRD and resistance measurement

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• 作者：Ming Li ; Wuming Yang ; Lixin Li ; Huixin Wang ; Shaowei Liang ; Chunxiao Gao
• 关键词：High pressure ; EDXRD ; Resistance ; Phase transition
• 刊名：Physica B
• 出版年：2011
• 出版时间：1 January 2011
• 年：2011
• 卷：406
• 期：1
• 页码：59-62
• 全文大小：421 K

文摘

High pressure behavior of CaB₆ with cubic crystal structure is investigated by means of energy dispersive X-ray diffraction and by employing in situ resistance measurement in a diamond anvil cell. Two newcome high pressure phase transitions are found with pressure ranging from ambient to 26 GPa. The first one at 12 GPa is a structural phase transition from CsCl-type structure to orthogonal structure, which is reflected by both the X-ray diffraction and the resistance variation. The other one at 3.7 GPa is suggested to be an electronic transition, which is observed only in resistance measurement. The diffraction pattern recovered while the pressure is released to 0 GPa with a pressure hysteresis over 11 GPa, which implies the reversibility of the two phase transitions. Bulk moduli of the cubic and orthogonal phases are estimated by fitting the data to a Brich–Murnaghan equation of state equal to 169.9 and 48.2 GPa, respectively.