采用金刚石对顶砧高压装置和同步辐射X射线衍射方法,在常温下对利蛇纹石的高压结构行为进行了研究。原位X射线衍射实验结果表明,利蛇纹石在压力高达31.9GPa时没有发生相变。利蛇纹石的等温状态方程通过三阶Birch-Mumaghan方程进行表述,得到V0=353.2(7)A^3,/(o=75(3)GPa,K0’=3.4(2)(北京同步辐射高压站实验结果)和V0=356.5(6)A3,K0=69(3)GPa,K0’=3.1(3)(上海光源微聚焦站实验结果),两次实验结果基本吻合。利蛇纹石的轴压缩性呈现各向异性(Kc〉Kb=Ka),这与蛇纹石的层状结构有关,在垂直于结构层方向,结构层之间靠氢键来连接,易压缩,压缩系数较大;而在平行结构层方向,压缩系数较小。
In situ high-pressure experiments of lizardite have been conducted by means of synchrotron X-ray diffraction with diamond anvil cell at room temperature. No phase transition occurs in the pressure range up to 31.9 GPa. Isothermal equation of state of lizardite can be well expressed by third-order Birch-Murnaghan equation of state, obtaining V0= 353.2(7) A3, K0= 75(3) GPa, K0'= 3.4(2) (BSRF data) and V0= 356.5(6) A3, K0= 69(3) GPa, K0'= 3.1(3) (SSRF data). These two sets of data show basically good consistency to each other. Anisotropy exists on axial compressibility of lizardite (Kc〉Kb=Ka), which can be ascribed to the layered structure of lizardite. The direction vertical to the structure layer are more compressible because the structure layers are collected by hydrogen bonds; while the direction parallel to the structure layer is less compressible for the reason of covalent bonds and ionic bonds