Structural, electronic, and dielectric properties of amorphous hafnium silicates
Structural, electronic, and dielectric properties of amorphous hafnium silicates
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DOI：
10.1063/1.3664780
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发表时间：
2011-12
影响因子：
3.2
通讯作者：
Tsung-Ju Chen;Chin-Lung Kuo
中科院分区：
文献类型：
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作者：
Tsung-Ju Chen;Chin-Lung Kuo
利用第一性原理计算，我们研究了非晶态Hf1-xSixO2在整个组成范围内的结构、电子和介电性质的演变。结果表明，富硅hf硅酸盐与富硅hf硅酸盐具有明显的结构特征。利用杂化密度泛函计算的电子带隙与实验结果吻合较好，随Si含量呈非线性变化。与以往的理论研究不同，我们的研究结果支持了介电常数与硅酸盐组成的非线性依赖关系，这主要是由于随着Si含量的增加，Hf原子的低频振动运动迅速减少。
Using first-principles calculations, we have investigated the evolution of the structural, electronic, and dielectric properties of amorphous Hf1-xSixO2 over the entire range of composition. Our results show that the Si-rich Hf-silicates possess distinct structural characteristics from the Hf-rich ones. The electronic band gaps calculated using hybrid density functional agree well with the experiments, exhibiting nonlinear variation with the Si content. Different from the previous theoretical studies, our results support a nonlinear dependence of the dielectric constants on the composition of silicates, which is mainly attributed to the rapid reduction of the low-frequency vibrational motions of Hf atoms with increasing the Si content.