电气石的原位高压X射线衍射研究

In situ high-pressure X-ray diffraction of natural tourmaline

使用金刚石对顶砧(DAC)高压装置和同步辐射光源,对黑色电气石进行了原位高压X射线衍射研究,实验最高压力达到27.8GPa。在研究的压力范围内,随着压力的升高,晶胞体积逐步被压缩,晶胞参数α的压缩率小于c。未观察到电气石的结构相变。利用Murnaghan状态方程(K′=4)对电气石的体积—压力数据进行拟合,获得的等热体积模量K_(298)为(183.5±4.2)GPa。

In situ high-pressure energy dispersive X-ray diffraction experiments on natural tourmaline have been carried out using diamond anvil cell(DAC) device with synchrotron radiation source. The pressure dependence of the lattice parameters of tourmaline is reported up to 27.8 GPa at room temperature. In the experimental pressure range, we have not observed the evidence of phase transition for tourmaline. The Murnaghan equation of state is used to fit the P-V data, assuming the pressure derivative K'=4, then the isothermal bulk modulus K_(298)=183.5±4.2 Gpa is obtained.