First-principles study of phase equilibria in Cu–Pt–Rh disordered alloys
First-principles study of phase equilibria in Cu–Pt–Rh disordered alloys
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Cu-Pt-Rh无序合金相平衡的第一性原理研究
DOI：
10.1088/0953-8984/21/41/415401
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发表时间：
2009
期刊：
影响因子：
--
通讯作者：
Koretaka Yuge
中科院分区：
文献类型：
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作者：
Koretaka Yuge
Cu-Pt-Rh 三元无序合金的相稳定性通过团簇扩展技术和基于第一性原理计算的蒙特卡罗统计模拟相结合来检验。伪二元ECI的符号表明相邻的Cu和Pt强烈偏好异原子对，Pt和Rh弱偏好异原子对，而Cu和Rh原子偏好同原子对，表明三元合金保留了组成二元合金的有序倾向。对于各种富 Pt 成分，随机合金在 T = 1200 K 时的形成能表现出负值，而在 x≤0.25 的贫 Pt 成分中，形成能具有正值。随机合金的计算亲和力显示了该合金的各种能量上有利的键：第一和第二最近邻（1-NN和2-NN）中的Cu-Pt键对于所有成分范围都是能量上优选的，1-NN中的Pt-Rh键在富含Pt的成分中是优选的，2-NN中的Pt-Rh和1-NN中的Rh-Cu键对所有成分都是不利的，并且在2-NN 不适合缺乏 Pt 的组合物。我们阐明，在 Cu-Pt-Rh 三元合金的整个成分范围内，二元合金中 1-NN 和 2-NN Cu-Pt、2-NN Pt-Rh 和 1-NN Cu-Rh 原子的有序趋势得到保留，而 1-NN Pt-Rh 和 2-NN Cu-Rh 原子的有序趋势显着取决于成分。
Phase stability of Cu–Pt–Rh ternary disordered alloys is examined by a combination of cluster expansion techniques and Monte Carlo statistical simulation based on first-principles calculation. The sign of pseudo-binary ECIs indicates that neighboring Cu and Pt strongly prefer unlike-atom pairs, Pt and Rh weakly prefer unlike-atom pairs, and Cu and Rh atoms prefer like-atom pairs, indicating that the ternary alloy retains the ordering tendency of the constituent binary alloys. The formation energy of a random alloy at T = 1200 K exhibits a negative sign for a wide range of Pt-rich compositions, while at Pt-poor compositions of x≤0.25, the formation energy has a positive value. Calculated affinities for the random alloy show the variety of energetically favored bonds for the alloy: Cu–Pt bonds in both first-and second-nearest neighbor (1-NN and 2-NN) are energetically preferred for all the composition range, the Pt–Rh bond in 1-NN is preferred at Pt-rich compositions, the Pt–Rh in 2-NN and Rh–Cu in 1-NN bonds are unfavored for all compositions, and the Rh–Cu bond in 2-NN is unfavored for Pt-poor compositions. We elucidate that the ordering tendency of 1-NN and 2-NN Cu–Pt, 2-NN Pt–Rh and 1-NN Cu–Rh atoms in constituent binary alloys is retained for the whole composition range of Cu–Pt–Rh ternary alloys, while that of 1-NN Pt–Rh and 2-NN Cu–Rh atoms significantly depends on composition.
影响因子：
3.7
作者：
Koretaka Yuge;Atsuto Seko;Y. Koyama;F. Oba;I. Tanaka
通讯作者：
Koretaka Yuge;Atsuto Seko;Y. Koyama;F. Oba;I. Tanaka
Cu75Pt25(111)表面的有序与偏析：第一性原理团簇扩展研究
DOI：
--
发表时间：
2007
期刊：
Physical Review B 76
影响因子：
--
作者：
Koretaka Yuge;Atsuto Seko;Akihide Kuwabara;Fumiyasu Oba;and Isao Tanaka
通讯作者：
and Isao Tanaka