硅酸盐玻璃和熔体中硅和铝的配位与局部结构:K边X射线吸收光谱研究

Coordination and Local Structure of Si and Al in Silicate Glasses and Melts:X ray Absorption Spectroscopic Study

硅酸盐玻璃和熔体中硅和铝的配位与局部结构：Ｋ边Ｘ射线吸收光谱研究＊李迪恩（中山大学地质系，广州５１０２７５）关键词硅酸盐玻璃和熔体硅和铝的配位Ｘ射线吸光谱高压下硅酸盐矿物和玻璃中的硅可以形成八面体配位［１］，但在通常的低压硅酸盐玻璃中，硅和铝为四面体...

The coordination and local structure of Si and Al in silicate glasses and melts have been studied using Si and Al K edge X ray absorption spectroscopy for the first time It has been verified that in SiO 2 P 2O 5 and Na 2O SiO 2 P 2O 5 joint phosphate silicate glasses,Si atoms remain tetrahedrally coordinated with oxygen when the content of P 2O 5 is below 32%mol,but partial Si atoms become octahedrally coordinated with oxygen when the content of P 2O 5 increases above 32%mol,and the proportion of the octahedrally coordinated Si atoms increases with the increasing content of P 2O 5 It has also been demonstrated that Al remains four fold coordinated with oxygen in ambient NaAlSi 2O 6 NaAlSi 3O 8 glasses, but in the same composition glasses quenched at 4 4 GPa and 1 575℃,partial Al atoms become five and six fold coordinated with oxygen,and at the same pressure and temperature,the proportions of five and six fold coordinated Al atoms increases with the increasing content of NaAlSi 2O 6 in the glasses Thus,the pressure induced coordination change of Al in aluminosilicate glasses and melts has been observed for the first time by Al K edge X ray absorption spectroscopy