CAJ | 학술논문

通过分子动力学模拟研究了金属钴和铁熔体从普通液态到过冷液态普通微观结构的性质.所计算两体分布函数与可获得的实验结果基本一致,从普通液态到过冷液态的局域结构中的原子配位数为11和12的分布几率随着温度的降低而变小,而原子的配位数大于12的分布几率反而增加,角分布函数位于55.有一个明显的峰,位于110°有一个宽展的峰,位于150°有一个肩膀,表明金属钴和铁熔体的微观局域结构要比规则的二十面体团簇的结构复杂得多.我们的模拟结果表明金属熔体中的二十面体短程序随着温度的降低而增加,并在过冷液态中而占优势.
통과분자동역학모의연구료금속고화철용체종보통액태도과랭액태보통미관결구적성질.소계산량체분포함수여가획득적실험결과기본일치,종보통액태도과랭액태적국역결구중적원자배위수위11화12적분포궤솔수착온도적강저이변소,이원자적배위수대우12적분포궤솔반이증가,각분포함수위우55.유일개명현적봉,위우110°유일개관전적봉,위우150°유일개견방,표명금속고화철용체적미관국역결구요비규칙적이십면체단족적결구복잡득다.아문적모의결과표명금속용체중적이십면체단정서수착온도적강저이증가,병재과랭액태중이점우세.
We have performed ab initio molecular dynamics simulations of metallic melts Co and Fe in stable and undercooled melts.The structural properties and their temperature dependence were studied.The calculated pair correlation functions are in agreement with available experimental data.Going from the stable liquid to the undercooled state.the fraction of coordination numbers 11 and 12 becomes lass but the fraction of coordination numbers more than 12 becomes more.The calculated bond-angle distributions show a prominent peak θ～55°,a broad peak θ～110°and a small shoulder θ～150°,indicating that the local structure of Co and Fe melts is more complex than the typical simple liquid structure and the simple icosahedral short-range order.The resuits of the pair analysis technique show that the icosahedral short-range order may grow with the decrease of the temperature and may become more prevalent in the undercooled state.