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
2期
370-378
,共9页
孙顺平%李小平%于赟%卢雅琳%臧冰%易丹青%江勇
孫順平%李小平%于赟%盧雅琳%臧冰%易丹青%江勇
손순평%리소평%우빈%로아림%장빙%역단청%강용
Al3Li金属间化合物%第一原理计算%点缺陷浓度%形成焓%Wagner–Schottky模型
Al3Li金屬間化閤物%第一原理計算%點缺陷濃度%形成焓%Wagner–Schottky模型
Al3Li금속간화합물%제일원리계산%점결함농도%형성함%Wagner–Schottky모형
Al3Li intermetallic%first-principle calculation%point defects density%formation enthalpy%Wagner–Schottky model
运用第一原理平面波赝势方法计算L12-Al3Li金属间化合物点缺陷的形成焓,并结合Wagner–Schottky模型,研究L12-Al3Li金属间化合物在523、673、823和1000 K时点缺陷浓度与成分之间的关系.结果表明:在这4个温度下,L12-Al3Li金属间化合物中Al空位浓度最小,Li空位浓度次之,Al反位和Li反位的缺陷浓度较大.Al反位和Li反位缺陷浓度在理想金属间化合物Al3Li化学计量比成分处基本相同,不过两种反位的缺陷浓度随着合金成分相对于化学计量比成分的偏离而变化显著,在富Al端Al反位缺陷浓度较大,在富Li端Li反位缺陷浓度较大.运用Arrhenius方程计算点缺陷的有效形成焓,结果显示Al反位和Li反位的有效形成焓较小且基本相同,Li空位次之,Al空位最大.
運用第一原理平麵波贗勢方法計算L12-Al3Li金屬間化閤物點缺陷的形成焓,併結閤Wagner–Schottky模型,研究L12-Al3Li金屬間化閤物在523、673、823和1000 K時點缺陷濃度與成分之間的關繫.結果錶明:在這4箇溫度下,L12-Al3Li金屬間化閤物中Al空位濃度最小,Li空位濃度次之,Al反位和Li反位的缺陷濃度較大.Al反位和Li反位缺陷濃度在理想金屬間化閤物Al3Li化學計量比成分處基本相同,不過兩種反位的缺陷濃度隨著閤金成分相對于化學計量比成分的偏離而變化顯著,在富Al耑Al反位缺陷濃度較大,在富Li耑Li反位缺陷濃度較大.運用Arrhenius方程計算點缺陷的有效形成焓,結果顯示Al反位和Li反位的有效形成焓較小且基本相同,Li空位次之,Al空位最大.
운용제일원리평면파안세방법계산L12-Al3Li금속간화합물점결함적형성함,병결합Wagner–Schottky모형,연구L12-Al3Li금속간화합물재523、673、823화1000 K시점결함농도여성분지간적관계.결과표명:재저4개온도하,L12-Al3Li금속간화합물중Al공위농도최소,Li공위농도차지,Al반위화Li반위적결함농도교대.Al반위화Li반위결함농도재이상금속간화합물Al3Li화학계량비성분처기본상동,불과량충반위적결함농도수착합금성분상대우화학계량비성분적편리이변화현저,재부Al단Al반위결함농도교대,재부Li단Li반위결함농도교대.운용Arrhenius방정계산점결함적유효형성함,결과현시Al반위화Li반위적유효형성함교소차기본상동,Li공위차지,Al공위최대.
@@@@Based on the first-principle pseudopotential plane-wave method, the formation enthalpies of point defects for L12-Al3Li intermetallic were calculated. Combining with Wagner–Schottky model, the point defect concentrations in L12-Al3Li at 523, 673, 823 and 1 000 K as function of composition were also investigated. The results show that the point defect concentrations at these investigated temperatures from small to big in sequence are Al vacancy, Li vacancy, Al anti-site and Li anti-site. The point defect concentrations of Al anti-site are similar to those of Li anti-site in stoichiometric L12-Al3Li composition. However, the point defect concentrations of Al anti-site and Li anti-site change evidently when the alloy composition is deviated from the stoichiometric L12-Al3Li composition, resulting in mainly Al anti-site in rich-Al alloy and mostly Li anti-site in rich-Li alloy. Using Arrhenius equation, the effective formation enthalpies of point defects for L12-Al3Li were calculated. It is found that the effective formation enthalpies from big to small in sequence are Al vacancy, Li vacancy, Al anti-site and Li anti-site.
