Stability and Metastability of Clusters in a Reactive Atmosphere: Theoretical Evidence for Unexpected Stoichiometries of MgMOx

被引：73

作者：

Bhattacharya, Saswata ^{[1
]}

Levchenko, Sergey V. ^{[1
]}

Ghiringhelli, Luca M. ^{[1
]}

Scheffler, Matthias ^{[1
]}

机构：

[1] Max Planck Gesell, Fritz Haber Inst, D-14195 Berlin, Germany

来源：

PHYSICAL REVIEW LETTERS | 2013年 / 111卷 / 13期

关键词：

GOLD CLUSTERS; AB-INITIO; MGO; APPROXIMATION; (MGO)(N); REAXFF;

D O I：

10.1103/PhysRevLett.111.135501

中图分类号：

O4 [物理学];

学科分类号：

0702 ;

摘要：

By applying a genetic algorithm and ab initio atomistic thermodynamics, we identify the stable and metastable compositions and structures of MgMOx clusters at realistic temperatures and oxygen pressures. We find that small clusters (M less than or similar to 5) are in thermodynamic equilibrium when x > M. The nonstoichiometric clusters exhibit peculiar magnetic behavior, suggesting the possibility of tuning magnetic properties by changing environmental pressure and temperature conditions. Furthermore, we show that density-functional theory with a hybrid exchange-correlation functional is needed for predicting accurate phase diagrams of metal-oxide clusters. Neither a (sophisticated) force field nor density-functional theory with (semi) local exchange-correlation functionals is sufficient for even a qualitative prediction.

引用

页数：5