Thallium under extreme compression. (8th September 2016)

• Record Type: Journal Article
• Authors: Cazorla, C; MacLeod, S G; Errandonea, D; Munro, K A; McMahon, M I; Popescu, C
• Is Part Of: Journal of physics. Volume 28:Number 44(2016)
• Publication Date: 2016-09-08
• Subjects: thallium -- x-ray diffraction -- ab initio calculations -- high pressure -- high temperature -- phase transition -- equation of state; Condensed matter -- Periodicals; Matière condensée -- Périodiques; Vaste stoffen; Vloeistoffen; Natuurkunde; Electronic journals; Computer network resources; 530.4105
• DOI: 10.1088/0953-8984/28/44/445401
• Languages: English
• ISSNs: 0953-8984

Abstract

Abstract: We present a combined theoretical and experimental study of the high-pressure behavior of thallium. X-ray diffraction experiments have been carried out at room temperature (RT) up to 125 GPa using diamond-anvil cells (DACs), nearly doubling the pressure range of previous experiments. We have confirmed the hcp–fcc transition at 3.5 GPa and determined that the fcc structure remains stable up to the highest pressure attained in the experiments. In addition, HP–HT experiments have been performed up to 8 GPa and 700 K by using a combination of XRD and a resistively heated DAC. Information on the phase boundaries is obtained, as well as crystallographic information on the HT bcc phase. The equation of state (EOS) for different phases is reported. Ab initio calculations have also been carried out considering several potential high-pressure structures. They are consistent with the experimental results and predict that, among the structures considered in the calculations, the fcc structure of thallium is stable up to 4.3 TPa. Calculations also predict the post-fcc phase to have a close-packed orthorhombic structure above 4.3 TPa.