铁的原子间相互作用及声子谱

根据近年发展起来的Mbius变换方法，从铁的结合能出发，反演计算出铁中原子间的相互 作用势.利用得到的相互作用势直接计算了原子力常数，并进而计算了铁的声子谱.计算中发 现，在研究铁中原子间相互作用时，仅考虑二体相互作用是不够的，还必须考虑三体相互作 用，采用Slater-Kirkwood型三体势，计算结果表明，在考虑三体势后，在三个主要对称方 向［1００］，［11０］，［111］上，计算结果与实验值得到了满意的符合. 关键词： 原子间相互作用势 声子谱 Mbius变换

THE INTERATOMIC INTERACTION AND PHONON DISPERSIONS IN IRON

In the present paper the interatomic interaction in iron is calculated from the cohesive energy by means of the Mbius transform formula.The atomic force const ants are calculated using the calculated potential and then the phonon dispersions.In the calculation it is found that only the two-body potential in the intera ction is insufficient,and the three-body potential also needs to be taken into a ccount.In the later calculation the Slater-Kirkwood type three-body potential is used and the calculated results of the phonon dispersions along three major dir ections 100],110] and 111] are in good agreement with experiment.