原子与分子物理学报
原子與分子物理學報
원자여분자물이학보
CHINESE JOURNAL OF ATOMIC AND MOLECULAR PHYSICS
2010年
1期
145-152
,共8页
第一性原理%Mg-Al-Ca合金%Laves相%电子结构
第一性原理%Mg-Al-Ca閤金%Laves相%電子結構
제일성원리%Mg-Al-Ca합금%Laves상%전자결구
first-principles%Mg-Al-Ca alloys%Laves phase%electronic structure
采用基于密度泛函理论的第一性原理方法,应用VASP (Vienna Ab-initio Simulation Package) 计算软件,研究了Mg-Al-Ca合金中三元Laves相,即Ca(Mg_(1-x),Al_x)_2和Al_2(Ca_(1-x),Mg_x) (x=0, 0.25, 0.50, 0.75, 1)在不同形态结构(C14, C15和C36)下的相稳定性及电子结构.计算所得的晶格常数和实验值吻合很好,形成能和相关能的计算用来研究三元Laves相的合金化能力和稳定性,结果表明:C14-Ca(Mg_(0.25),Al_(0.75))_2具有很好的合金化能力,而C15-CaAl_2具有很好的结构稳定性.态密度和电荷密度的计算用来研究Mg-Al-Ca合金中三元Laves相稳定性的内在微观机制.
採用基于密度汎函理論的第一性原理方法,應用VASP (Vienna Ab-initio Simulation Package) 計算軟件,研究瞭Mg-Al-Ca閤金中三元Laves相,即Ca(Mg_(1-x),Al_x)_2和Al_2(Ca_(1-x),Mg_x) (x=0, 0.25, 0.50, 0.75, 1)在不同形態結構(C14, C15和C36)下的相穩定性及電子結構.計算所得的晶格常數和實驗值吻閤很好,形成能和相關能的計算用來研究三元Laves相的閤金化能力和穩定性,結果錶明:C14-Ca(Mg_(0.25),Al_(0.75))_2具有很好的閤金化能力,而C15-CaAl_2具有很好的結構穩定性.態密度和電荷密度的計算用來研究Mg-Al-Ca閤金中三元Laves相穩定性的內在微觀機製.
채용기우밀도범함이론적제일성원리방법,응용VASP (Vienna Ab-initio Simulation Package) 계산연건,연구료Mg-Al-Ca합금중삼원Laves상,즉Ca(Mg_(1-x),Al_x)_2화Al_2(Ca_(1-x),Mg_x) (x=0, 0.25, 0.50, 0.75, 1)재불동형태결구(C14, C15화C36)하적상은정성급전자결구.계산소득적정격상수화실험치문합흔호,형성능화상관능적계산용래연구삼원Laves상적합금화능력화은정성,결과표명:C14-Ca(Mg_(0.25),Al_(0.75))_2구유흔호적합금화능력,이C15-CaAl_2구유흔호적결구은정성.태밀도화전하밀도적계산용래연구Mg-Al-Ca합금중삼원Laves상은정성적내재미관궤제.
We have carried out the first-principles theoretical calculations based on density-functional theory to investigate the phase stability and electronic structure of Ca(Mg_(1-x),Al_x)_2 and Al_2(Ca_(1-x),Mg_x) (x=0, 0.25, 0.50, 0.75, 1) with C14-, C15- and C36- structures in Mg-Al-Ca ternary Laves phases. The obtained lattice constants are in good agreement with the experimental values. The heat of formation and cohesive energy are calculated and used to study the stability of Ca(Mg_(1-x),Al_x)_2 and Al_2(Ca_(1-x),Mg_x) Laves phases. The results show that C14-Ca(Mg_(0. 25),Al_(0.75)) has the strongest alloying ability and C15-CaAl_2 has the best stability of all the investigated Laves phases in Mg-Al-Ca alloy. The density of states (DOS) and charge density distribution are used to study the underlying mechanism of structure and phase stability of ternary Laves phases in Mg-Al-Ca alloys.
