微观相场法反演L1_2结构的原子间相互作用势  

Inversion of the First Nearest Neighbor Interchange Interaction Potential in L1_2 Structure by Microscopic Phase-Field Simulation

作　　者：徐聪[1] 陈铮[1] 卢艳丽[1] 钟汉文[1] 张静[1] 苗海川[1] 

机构地区：[1]西北工业大学凝固技术国家重点实验室,陕西西安710072

出　　处：《稀有金属材料与工程》2010年第6期1027-1030,共4页Rare Metal Materials and Engineering

基　　金：国家自然科学基金(50941020;10902086);中国博士后科学基金(2007040218);陕西省自然科学基金(SJ08-ZT05)

摘　　要：基于微观相场理论,根据Khachaturyan的占位几率和能量关系方程,推导出L12结构的第一近邻原子间相互作用势与长程序参数关系的反演方程-4w1η/kBT=In(1-η)[1-c(1+3·η)]/(1+3·η)[1-c(1-η)]根据该方程,只需输入根据相图中L12结构相变点的温度和原子浓度,就可以计算出不同温度和原子浓度下的L12结构的第1近邻原子间相互作用势,计算结果与第1性原理及其他方法计算的值接近;同时在计算过程中发现了L12结构的第1近邻原子间相互作用势在析出L12相的相图范围内随温度和原子浓度变化。Based on the microscopic phase-field theory, the inversion formula of the connection between the first nearest neighbor interchange potential W1 and the long range order parameter η, i.e. -4W1.η/kBT=ln（1-η）[1-c（1＋3.η）]/（1＋3.η）[1-c（1-η）] was concluded according to the formula for the connection between occupation probability and free energy by Khachaturyan. According to the formula, W1 of L12 structure can be simply calculated under different conditions of atomic concentration and temperature only by substituting the temperature and atomic concentration of L1 structure transformation point. The calculated result is close to the numerical value by first-principle and other methods. At the same time, it is found that W1 of L12 structure was affected by atomic concentration and temperature in the phase diagram range of precipitated L12.

关 键 词：原子间相互作用势 反演 微观相场 L12结构 

分 类 号：O562.4[理学—原子与分子物理]