中国有色金属学报
中國有色金屬學報
중국유색금속학보
THE CHINESE JOURNAL OF NONFERROUS METALS
2013年
8期
2147-2155
,共9页
孙顺平%李小平%雷卫宁%王洪金%汪贤才%江海锋%李仁兴%江勇%易丹青
孫順平%李小平%雷衛寧%王洪金%汪賢纔%江海鋒%李仁興%江勇%易丹青
손순평%리소평%뢰위저%왕홍금%왕현재%강해봉%리인흥%강용%역단청
L1 2-Al 3 Sc%点缺陷结构%第一性原理计算%成键行为%杂化
L1 2-Al 3 Sc%點缺陷結構%第一性原理計算%成鍵行為%雜化
L1 2-Al 3 Sc%점결함결구%제일성원리계산%성건행위%잡화
L1 2-Al 3 Sc%point defect structures%first-principles calculation%bonding behavior%hybridization
运用第一性原理平面波赝势方法计算金属间化合物L12-Al 3 Sc的基本物性,并通过计算点缺陷形成能推测L12-Al 3 Sc点缺陷的主要存在形式,结合电荷密度和态密度的分析揭示L12-Al 3 Sc的成键行为。结果表明:L12-Al 3 Sc的晶格常数为4.107?,体模量为86.5 GPa,形成焓为?43.83 kJ/mol。L12-Al 3 Sc的点缺陷主要为Al亚晶格上的Al空位和Sc反位缺陷。L12-Al 3 Sc中Sc空位与Al反位缺陷的形成能较为接近,表明富Al合金中Sc空位和Al反位缺陷易于共同存在;Sc反位缺陷的形成能小于Al空位的,表明富Sc合金的点缺陷为Sc反位缺陷。L12-Al 3 Sc的成键电荷密度呈纺锤状,表现出Sc d-Al p的轨道杂化效应,其杂化轨道主要为Sc dz2-Al pz轨道杂化。
運用第一性原理平麵波贗勢方法計算金屬間化閤物L12-Al 3 Sc的基本物性,併通過計算點缺陷形成能推測L12-Al 3 Sc點缺陷的主要存在形式,結閤電荷密度和態密度的分析揭示L12-Al 3 Sc的成鍵行為。結果錶明:L12-Al 3 Sc的晶格常數為4.107?,體模量為86.5 GPa,形成焓為?43.83 kJ/mol。L12-Al 3 Sc的點缺陷主要為Al亞晶格上的Al空位和Sc反位缺陷。L12-Al 3 Sc中Sc空位與Al反位缺陷的形成能較為接近,錶明富Al閤金中Sc空位和Al反位缺陷易于共同存在;Sc反位缺陷的形成能小于Al空位的,錶明富Sc閤金的點缺陷為Sc反位缺陷。L12-Al 3 Sc的成鍵電荷密度呈紡錘狀,錶現齣Sc d-Al p的軌道雜化效應,其雜化軌道主要為Sc dz2-Al pz軌道雜化。
운용제일성원리평면파안세방법계산금속간화합물L12-Al 3 Sc적기본물성,병통과계산점결함형성능추측L12-Al 3 Sc점결함적주요존재형식,결합전하밀도화태밀도적분석게시L12-Al 3 Sc적성건행위。결과표명:L12-Al 3 Sc적정격상수위4.107?,체모량위86.5 GPa,형성함위?43.83 kJ/mol。L12-Al 3 Sc적점결함주요위Al아정격상적Al공위화Sc반위결함。L12-Al 3 Sc중Sc공위여Al반위결함적형성능교위접근,표명부Al합금중Sc공위화Al반위결함역우공동존재;Sc반위결함적형성능소우Al공위적,표명부Sc합금적점결함위Sc반위결함。L12-Al 3 Sc적성건전하밀도정방추상,표현출Sc d-Al p적궤도잡화효응,기잡화궤도주요위Sc dz2-Al pz궤도잡화。
The first-principles pseudopotential plane-wave calculation was used to study the energies and the electronic properties of point defects for L1 2-Al 3 Sc intermetallic. According to the calculation and comparison of the formation energy of point defect structures, the geometrical configuration of point defects in L1 2-Al 3 Sc intermetallic was analyzed. Combining with densities of states and charge densities, the effect of bonding behavior on electronic structure was investigated emphatically. The results show that the lattice constant of L12-Al3Sc is 4.107 ?,bulk modulus is 86.5 GPa, and formation enthalpy is?43.83 kJ/mol. These calculation results also suggest that the point defects in the Al sublattices, i.e., Al vacancy and Sc anti-site, are more favorable than those in the Sc sublattices for the stoichiometric compound Al3Sc in the L12 structure, but Sc vacancy and Al anti-site defect coexist in rich-Al alloy, and mainly Sc anti-site defect can be found in rich-Sc alloy. The Al vacancy-induced charge density shows the spindle-like bonding characteristic, and Sc dz2-Al pz orbital hybridization is depicted.