CAJ | 학술논문

计算了SrTiO3-δ(δ=0,δ=0.125)体系电子结构,分析了氧空位对SrTiO3晶体的价键结构、能带、态密度、分波态密度、差分电荷密度的影响.所有计算都是基于密度泛函理论(DFT)框架下的第一性原理平面波超软赝势方法.计算结果表明:当氧空位浓度δ=0.125时,空位在母体化合物SrTiO3中引入了大量的传导电子,费米能级进入导带,体系显示金属型导电性.由于空位掺杂,导带底附近的态密度发生了畸变,刚性能带模型不再适合描述SrTiO2.875体系.同时,在导带底附近距离费米能级0.3eV处引入了空位能级,这和实验测得的SrTiO3材料内中性氧空位的电离能约为0.4eV相符.此外,Mulliken布局分析、分波态密度和差分电荷密度分析表明,该空位能级主要由与其最近邻的两个Ti原子的3d电子态贡献,并且由该空位引入的导电电子大部分都局域在空位最近邻的两个Ti原子周围.最后,计算了三种典型平衡条件下SrTiO3晶体内中性氧空位的形成能.
계산료SrTiO3-δ(δ=0,δ=0.125)체계전자결구,분석료양공위대SrTiO3정체적개건결구、능대、태밀도、분파태밀도、차분전하밀도적영향.소유계산도시기우밀도범함이론(DFT)광가하적제일성원리평면파초연안세방법.계산결과표명:당양공위농도δ=0.125시,공위재모체화합물SrTiO3중인입료대량적전도전자,비미능급진입도대,체계현시금속형도전성.유우공위참잡,도대저부근적태밀도발생료기변,강성능대모형불재괄합묘술SrTiO2.875체계.동시,재도대저부근거리비미능급0.3eV처인입료공위능급,저화실험측득적SrTiO3재료내중성양공위적전리능약위0.4eV상부.차외,Mulliken포국분석、분파태밀도화차분전하밀도분석표명,해공위능급주요유여기최근린적량개Ti원자적3d전자태공헌,병차유해공위인입적도전전자대부분도국역재공위최근린적량개Ti원자주위.최후,계산료삼충전형평형조건하SrTiO3정체내중성양공위적형성능.
The electronic structure calculations including the Mulliken population analysis,band structure,density of states (DOS),partial density of states (PDOS) and electron density difference on SrTiO3-δwithδ=0 and δ=0.125 were performed by the first-principles calculation of plane wave ultrasoft pseudo-potential technology based on the density function theory (DFT).The calculated results revealed that due to the oxygen(O) vacancy electron doping,the Fermi level moved into conduction bands(CBs) for SrTiO3-δ with δ=0.125 and the system showed metallic behavior.There was a new defect level below the bottommost of CBs when one 0 vacancy was introduced.The 3d states of the two Ti atoms nearest to the vacancy made significant contribution to it.The electrons introduced by the O vacancy were largely localized on the two nearest Ti atoms.Furthermore,the formation energies of neutral O vacancy were calculated in three typical equilibrium conditions.