【摘要】 基于密度泛函理论(DFT),用完全势能线性缀加平面波方法(FPLAPW)计算模拟了MnO2的同质多相变体(金红石型结构、CaCl2型结构、黄铁矿型结构),通过计算,预测了β-MnO2在5 GPa时从金红石型结构转变为CaCl2型结构,在20 GPa时进一步转变为黄铁矿型结构。另外,还总结和比较了几种金红石型结构二氧化物的压致相变特点,得出第Ⅳ主族元素的金红石型结构氧化物有很好的规律性,发生的相变序列基本一致;并随着金属阳离子半径的增大,发生相变的压力值也相应地递减,各氧化物的体积模量值相应地减小。更多还原

【Abstract】 First-principle calculations of MnO₂ polymorphisms（rutile-type,CaCl₂-type and pyrite-type） have been carried out with the full potential linearized augmented plane wave（FPLAPW） method.Through the calculations,we predict that the rutile-type MnO₂ can transform to CaCl₂-type at 5GPa,and then transform to pyrite-type at 20GPa.Furthermore,we summary the characteristic of several rutile-structure metal dioxide phases transformation under high pressure and conclude that the group Ⅳ element dioxides have similar sequence of the phase transition.In general,the pressure induced phase transformations of these group Ⅳ element dioxide take place at lower pressure with the increase of cations radii and decrease of the value of bulk moduli.更多还原