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使用金刚石对顶砧高压装置(DAC)和同步辐射光源,对天然白钨矿进行了原位高压能量色散X射线衍射(EDXD)研究,实验最高压力为16.0GPa。在实验压力范围内观察到了一次白钨矿结构→钨锰铁矿结构的可逆相变:压力小于5.3GPa时为白钨矿结构(I41/a),在5.3～12.3GPa压力区间内为白钨矿结构与钨锰铁矿结构(P2/c)并存,大于12.3GPa时完全相变为钨锰铁矿结构。从键长、配位数和配位多面体角度对白钨矿→钨锰铁矿结构的相变机制进行了解释。
In situ high-pressure energy dispersive X-ray diffraction (EDXD) studies on natural scheelite using a diamond anvil cell top (DAC) and a synchrotron radiation source were carried out. The maximum experimental pressure was 16.0 GPa. A reversible phase transition from scheelite structure to wolframite structure was observed in the experimental pressure range: scheelite structure (I41 / a) at pressure less than 5.3 GPa and white tungsten in pressure range 5.3 ~ 12.3 GPa The ore structure coexists with the wolframite structure (P2 / c), and when it is larger than 12.3 GPa, it completely transforms into the wolframite structure. The phase transformation mechanism of scheelite → wolframite structure is explained from bond length, coordination number and coordination polyhedron.