portlandite;
high pressure;
equation of state;
thermo-elasticity;
X-ray diffraction;
entropy;
D O I:
10.1080/0895795031000109670
中图分类号:
O4 [物理学];
学科分类号:
0702 ;
摘要:
An equation of state (EoS) for Ca(OH)(2) portlandite has been obtained through measurements of pressure and temperature dependence of volume by means of in-situ X-ray observation. The bulk modulus and its pressure derivative at zero pressure calculated using third-order Birch-Mumaghan's equation of state is 33.1 GPa and 4.2 at 300 K, respectively. The unit cell parameters and the volumes have been also determined at 573 K and 673 K. Temperature derivatives of the bulk modulus and its pressure derivative have been calculated to be -0.022 GPa/K and 0.0072 K-1, respectively. Thermal expansion coefficient of portlandite has been calculated from the EoS. The pressure dependence of entropy has been obtained from the present thermo-elastic parameters.