Zn-Mg合金的长程Finnis-Sinclair势

Long-range Finnis-Sinclair potential for Zn-Mg alloy

通过拟合Mg的晶格能、晶格常数、弹性常数,并将其与前人的结果相比较后获得了描述Mg的最优长程Finnis-Sinclair(F-S)势函数参数,使用同样方法并引入修正因子后得到了Zn的长程F-S势参数.基于单质Zn,Mg的F-S势参数,进一步拟合合金Mg21Zn25,MgZn2,Mg2Zn11的晶格常数、晶格能获得Zn-Mg原子对的F-S势参数,构建了整套描述Zn-Mg合金的长程F-S势参数.在此基础上,对Zn,Mg单质及其合金在300K下进行了分子动力学模拟验证,并通过与其完美晶体结构的比较证明了本套势参数对Zn-Mg合金描述的适用性.最终得到了Zn-Mg合金的长程F-S势函数参数.

A set of optimal long-range Finnis-Sinclair （F-S） potential parameters of single Mg are achieved by fitting the lattice energy,lattice constants,and elastic constants to experimental results.With the same method,the set of the F-S potential parameters of single Zn are obtained through the introduction of modifying factor to the repulsive term.Finally,the lattice energy and lattice constants of Mg21 Zn25,MgZn2 and Mg2Zn11 alloys are further fitted to achieve the F-S potential parameters of Zn-Mg based on the previous F-S potential parameters of Mg-Mg and Zn-Zn.After that,a series of molecular dynamics simulations of single Mg,Zn,and Mg21 Zn25,MgZn2,Mg2Zn11 alloys is performed at 300 K with the achieved F-S potential parameters,thereby proving the F-S potential parameters to be appropriate for the description of Zn-Mg alloys.The long-range F-S potential parameters of Zn and Zn,Mg and Mg,Zn and Mg are obtained.