掺锰铌酸锂晶体第一性原理研究  

First principles study of Mn-doped LiNbO_3

作　　者：雷晓蔚[1] 林竹[2] 赵辉[2] 

机构地区：[1]重庆文理学院物理系,重庆402160 [2]天津师范大学物理与电子信息学院,天津300387

出　　处：《原子与分子物理学报》2010年第5期1005-1010,共6页Journal of Atomic and Molecular Physics

基　　金：重庆市教育委员会科学技术研究项目(KJ091212);辽宁省自然科学基金(20082192)

摘　　要：利用第一性原理研究了Mn:LiNbO_3晶体的电子结构和光学性质.结果表明,Mn掺杂产生了杂质能级,主要由Mn的d态轨道贡献.杂质能级与导带之间的带隙小于理想LiNbO_3晶体导带与价带之间宽度,降低了电子跃迁所需能量.同时,掺杂也降低了各原子的电子轨道能量.晶体中最高占据轨道不再是O的2p轨道,而是Mn的d轨道.掺杂离子在晶体中同时充当电子的施主与受主.静态介电常数在掺杂后有明显的增大.Mn的掺杂使晶体在可见光区域的光学性质产生变化,并使晶体的吸收谱在可见光区域产生吸收峰.The electronic structure and optical properties of Mn-doped lithium niobate crystals （Mn：LiNbO3） have been studied with the first principles in the paper. It is found that there is impurity energy level at 0eV which was contributed by the d electrons of Mn. The gap between impurity level and conduction band is much smaller than that between the conduction band and value band of the perfect LiNbO3. Doping can reduce the energy of the transition of different atomic orbits as well as the level of each electronic orbit. The highest occupied orbit is the d orbit of Mn rather than the 2p orbit of O in the perfect LiNbO3. The dopant can be both the acceptor and the donor of electrons in the crystal. The static dielectric function has a clear increase after doping. A great change of optical properties is found in Mndoping LiNbO3 crystal and there are absorption peaks in the visible range.

关 键 词：第一性原理 铌酸锂 掺杂 电子结构 吸收谱 

分 类 号：O469[理学—凝聚态物理] O474[理学—电子物理学]