Lead phosphate Pb-3(PO4)(2) was investigated by in situ synchrotron radiation X-ray diffraction and X-ray absorption near-edge structure (XANES) combined with diamond anvil cell technique up to 60.9 GPa. A pressure-induced phase transition of Pb-3(PO4)(2) was observed from monoclinic (C2/c) to trigonal ( ) phases at about 1.7 GPa at room temperature. The high-pressure annealing experiment indicates that the trigonal phase of Pb-3(PO4)(2) is stable at least up to 60.9 GPa. Isothermal pressure-volume relationship of trigonal Pb-3(PO4)(2) is well described by the third-order Birch-Murnaghan equation of state with V-0 = 533(1) angstrom(3), K-0 = 89(4) GPa and K-0(') = 5.8(2). In trigonal Pb-3(PO4)(2), the a-axis is more compressible than the c-axis, showing an anisotropy elasticity. XANES results reveal the evolution of Pb local environment, i.e. the first-shell coordination number of Pb1 changes from 9 to 12 and the average Pb-O bond length increases at the crossover of C2/c-to- phase transition. Publication name | PHASE TRANSITIONS, 87 (12):1255-1264; 10.1080/01411594.2014.953504 DEC 2 2014 | Author(s) | Qin, Fei; Wu, X.; Zhai, S. M.; Qin, S.; Yang, K.; Chen, D. L.; Li, Y. C. | Corresponding author | WU, X. xiang.wu@pku.edu.cn Peking Univ, Sch Earth & Space Sci, Key Lab Orogen Belts & Crustal Evolut, Beijing 100871, Peoples R China. | Author(s) from IGCAS | ZHAI S.M. | View here for the details
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