论文标题
从随机采样有序构型中混合热力学和局部结构
The Mixing Thermodynamics and Local Structure of High-entropy Alloys from Randomly Sampled Ordered Configurations
论文作者
论文摘要
提出了一种将高熵合金作为在给定晶格上随机采样,有序配置的合奏进行建模的一般方法。事后将统计力学应用于合成和温度的函数,包括混合和局部结构的自由能。使用随机抽样来解决与大量组件建模合金所需的高计算成本。这样做还提供了严格的合并标准,包括由于随机抽样而导致的噪声定量,以及估计将此噪声降低到所需/所需水平所需的其他样本数量。该方法适合多种情况:i)高熵合金,标准晶格模型成本高昂; ii)“中”熵合金,熵和焓都起着重要作用; iii)具有剩余短距离顺序的合金。二元至5组分合金用于案例,为案例,预测的混溶性与实验表现出极好的一致性。
A general method is presented for modeling high entropy alloys as ensembles of randomly sampled, ordered configurations on a given lattice. Statistical mechanics is applied post hoc to derive the ensemble properties as a function of composition and temperature, including the free energy of mixing and local structure. Random sampling is employed to address the high computational costs needed to model alloys with a large number of components. Doing so also provides rigorous convergence criteria, including the quantification of noise due to random sampling, and an estimation of the number of additional samples required to lower this noise to the needed/desired levels. This method is well-suited for a variety of cases: i) high entropy alloys, where standard lattice models are costly; ii) "medium" entropy alloys, where both the entropy and enthalpy play significant roles; and iii) alloys with residual short-range order. Binary to 5-component alloys of the group-IV chalcogenides are used as case examples, for which the predicted miscibility shows excellent agreement with experiment.