掺铁铌酸锂晶体第一性原理研究

First principles study of Fe-doped LiNbO_3

利用第一性原理计算方法研究铁掺杂铌酸锂晶体的电子结构和光学性质,所有计算采用广义梯度近似下的平面波超软赝势方法,得到如下结论:掺杂产生的杂质能级,主要由铁的d轨道贡献.掺杂降低了电子跃迁所需能量,同时也降低了各原子的电子轨道能量.掺杂离子在晶体中既是电子的施主又是受主.铁的掺杂使铌酸锂晶体的能量损失函数有较大的增加,对光存储的效率有一定影响.铁的掺杂使晶体的光学性质在可见光低能范围发生变化,吸收谱在可见光区域产生吸收峰,有利于晶体全息存储的应用.

By using the ultra-soft pseudo-potential approach of the plane wave and generalized gradient approximation, the electronic structure and optical properties of Fe-doped lithium niobate have been calculated with the first principles. There is doping state at 0eV caused by the d electrons of Fe. Doping of Fe can reduce the energy of the transition of different atom orbits and the electron orbits. The dopant can be both the acceptor and the donor of electrons in the crystal. The loss function of Fe： LiNbOa increases and the efficiency of holographic data storage is reduced owing to the doping of Fe. A change of optical properties is found in doping crystal in the visible low energy range, and there are absorption peaks in this range. It＇s benefit to the holographic data storage.