(1. 四川大學(xué) 原子與分子物理研究所， 成都 610065；
2. 中國(guó)工程物理研究院， 綿陽(yáng) 621900)
摘 要: 在全電子水平上， 基于廣義梯度近似密度泛函和全勢(shì)能線性綴加平面波方法， 計(jì)算了不同Al含量LaNi5-xAlx(x=0, 0.5, 1.0)的晶體結(jié)構(gòu)、 能帶結(jié)構(gòu)、 狀態(tài)密度等特征。 對(duì)LaNi5的計(jì)算表明： GGA Perdew96的計(jì)算結(jié)果可信， 自旋極化對(duì)優(yōu)化結(jié)構(gòu)和能量的影響不明顯； 對(duì)LaNi4Al的研究表明Al原子最可能取代3g位的Ni原子； 對(duì)LaNi4.5Al0.5的優(yōu)化結(jié)構(gòu)與實(shí)驗(yàn)結(jié)果一致。 隨著Al含量的升高， 晶胞能量、 費(fèi)米面能量升高， 如從LaNi5， LaN4.5Al0.5到LaNi4Al， 費(fèi)米面能量從-10.591、 -10.134 eV升高到-9.441 eV， 而Ef上的態(tài)密度和材料對(duì)應(yīng)的低溫比熱容則急劇下降， 態(tài)密度從11.81、 8.86急劇降低到1.61 eV/f.u.。 并計(jì)算給出了LaNi4.5Al0.5的能帶結(jié)構(gòu)、 狀態(tài)密度圖。
關(guān)鍵字: LaNi4Al； LaNi4.5Al0.5 ; 全勢(shì)能線性綴加平面波法(FLAPW)
（1. Institute of Atomic and Molecular Physics,
Sichuan University, Chengdu 610065, China;
2. Chinese Academy of Engineering Physics,
Mianyang 621900, China）
Abstract: Based on the generalized gradient approximation (GGA) of density of function and the full potential linearized augmented wave (FLAPW), the equilibrium structure , energy bands and density of states were calculated for LaNi5-xAlx. The results show that, For LaNi5, the calculation by GGA perdew96 is better than those of other methods, and the spin-polarization have no obvious effect on the optimized structure and energy. For LaNi4Al, the result indicates that nickel is most likely substituted by aluminum on the 3g site, and the optimized structure for LaNi4.5Al0.5 exactly agrees with the experimental results. With the increasing content of aluminum, the Fermi energy and density of states sharply decrease in the order from LaNi5 to LaNi4.5Al0.5 and LaNi4Al, the Fermi Energy increases from -10.591, -10.134 eV to -9.441 eV, and the density of states (DOS) of Ef decreases from 11.81, 8.86 to 1.61 eV/f.u.. The energy band structure and density of states for LaNi4.5Al0.5 were firstly calculated.
Key words: LaNi4Al; LaNi4.5Al0.5; electric structure; full-potential linearized augmented plane wave
