Phase Transition and Melting Curves of Calcium Fluoride via Molecular Dynamics Simulations
ZENG Zhao-Yi1,2, CHEN Xiang-Rong1,2,3, ZHU Jun2, HU Cui-E 1,3
1Institute of Atomic and Molecular Physics, Sichuan University, Chengdu 6100652College of Physical Science and Technology, Sichuan University, Chengdu 6100643International Centre for Materials Physics, Chinese Academy of Sciences, Shenyang 110016
Phase Transition and Melting Curves of Calcium Fluoride via Molecular Dynamics Simulations
1Institute of Atomic and Molecular Physics, Sichuan University, Chengdu 6100652College of Physical Science and Technology, Sichuan University, Chengdu 6100643International Centre for Materials Physics, Chinese Academy of Sciences, Shenyang 110016
摘要The phase transition and melting curves of CaF2 are investigated by using the general utility lattice programme (GULP) via the shell model with molecular dynamics method. By calculating the entropy H (at 0K) and Gibbs free energy G* (at 300K), we find that the phase transition pressure from the face-centred cubic (fcc) structure to the orthorhombic structure is 11.40GPa and 9.33GPa at 0K and 300K, respectively. The modified melting point of the fcc CaF2 is in the range of 1650--1733K at 0GPa. All these results are well consistent with the available experimental data and other theoretical results. We also obtain that the melting temperature of high pressure phase is 990--1073K at 10GPa. Moreover, the temperature dependences of the elastic constants Cij, bulk module B and shear module G are also predicted.
Abstract：The phase transition and melting curves of CaF2 are investigated by using the general utility lattice programme (GULP) via the shell model with molecular dynamics method. By calculating the entropy H (at 0K) and Gibbs free energy G* (at 300K), we find that the phase transition pressure from the face-centred cubic (fcc) structure to the orthorhombic structure is 11.40GPa and 9.33GPa at 0K and 300K, respectively. The modified melting point of the fcc CaF2 is in the range of 1650--1733K at 0GPa. All these results are well consistent with the available experimental data and other theoretical results. We also obtain that the melting temperature of high pressure phase is 990--1073K at 10GPa. Moreover, the temperature dependences of the elastic constants Cij, bulk module B and shear module G are also predicted.
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2008, Vol. 25 
