氟磷灰石、氯磷灰石和羟基磷灰石电子结构的第一性原理研究  

First-Principles Study of Electronic Structure of Fluorapatite,Chlorapatite and Hydroxyapatite

作　　者：张小武 谢俊[1,2,3] 李龙江 王贤晨[1,2,3] 张覃 

机构地区：[1]贵州大学矿业学院,贵州贵阳550025 [2]喀斯特地区优势矿产资源高效利用国家地方联合工程实验室,贵州贵阳550025 [3]贵州省非金属矿产资源综合利用重点实验室,贵州贵阳550025

出　　处：《矿冶工程》2017年第6期84-90,共7页Mining and Metallurgical Engineering

基　　金：贵州省高层次创新型人才培养((2015)4012)

摘　　要：基于密度泛函理论(DFT)的第一性原理,研究了氟磷灰石、氯磷灰石和羟基磷灰石的电子结构,讨论了不同通道离子(F-、Cl-、OH-)对磷灰石电子结构的影响。能带分析表明:氟磷灰石、氯磷灰石和羟基磷灰石均为绝缘体,其带宽分别为5.600、5.384和3.577 e V。态密度分析表明:通道离子对3种磷灰石的态密度影响较大,氟磷灰石与氯磷灰石导带部分有Ca1 3d轨道和Ca2 3d轨道的贡献;羟基磷灰石态密度导带部分仅有Ca2 3d轨道的贡献,导致Ca2还原性降低;羟基磷灰石态密度向低能级方向移动,形成新的深部价带;Cl的态密度较F的态密度向高能级方向移动,导致形成新的中部价带-12.5~14.0 e V,该价带仅由Cl 3s轨道组成。Mulliken电荷布居及键布居表明:F得电荷能力强于Cl,主要是F的2p轨道得电荷能力强于Cl的3p轨道;3种磷灰石中的O—P键布居接近且均较大,共价性较强,F—Ca与Cl—Ca布居接近,但F—Ca键长小于Cl—Ca键长,F—Ca结合作用强于Cl—Ca。The structure and electronic properties of fluorapatite,chlorapatite and hydroxyapatite were investigated based on DFT theory,and the effect of channel-ions（F-,Cl-,OH-） on electronic structure was discussed. Energy bans analysis indicates that fluorapatite,chlorapatite and hydroxyapatite are all insulators,with a bandwidth of 5. 600 e V,5.384 e V,and 3.577 e V. DOS analysis indicates that channel-ions have greater influence on the DOS of three kinds of apatite. The part of conduction band of fluorapatite and chlorapatite is attributed to Ca1 3 d orbitals and Ca2 3 d orbital,while the part of conduction band of hydroxyapatite is contributed only by Ca2 3 d orbital, leading to DOS of hydroxyapatite moving towards lower energy level and forming a new deep valence band. The DOS of Cl moves towards higher energy compared to the DOS of F,forming a new central valence band（-12. 5 ~ 14. 0 e V）,which is only composed of Cl 3 s orbital. The Mulliken population of charge and band indicates that F is more powerful to get charge than Cl,mainly because F 2 p orbital is more powerful to get charge capacity compared to Cl 3 p orbital. The O—P bands in three kinds of apatite have similar and larger population,and stronger covalency. Although F—Ca population is similar to Cl—Ca population,the bond length of F—Ca is smaller than the Cl—Ca,resulting in the interaction of F—Ca stronger than Cl—Ca.

关 键 词：氟磷灰石 氯磷灰石 羟基磷灰石 电子结构 第一性原理 

分 类 号：O76[理学—晶体学]