相图
纳米颗粒
材料科学
粒子(生态学)
化学稳定性
相(物质)
氧化铁
密度泛函理论
表面能
氧气
热力学
曲面(拓扑)
化学物理
物理化学
化学
纳米技术
计算化学
冶金
物理
数学
有机化学
几何学
地质学
海洋学
作者
Yu Meng,Xingwu Liu,Miaomiao Bai,Wenping Guo,Dong‐Bo Cao,Yong Yang,Yongwang Li,Xiaodong Wen
标识
DOI:10.1016/j.apsusc.2019.03.005
摘要
The surface energies and the morphologies of three iron oxides (α-Fe2O3, Fe3O4, and FeO) are systematically investigated by Density Functional Theory (DFT) employing PBE and PBE+U methods. The surface energies are computed under various O chemical potential which is directly related to atmosphere condition. Compared with available experimental observations, PBE provides reasonable prediction on surface stability of all three oxides while the results of PBE+U are not well consistent with experiments for Fe2O3. Based on the Wulff construction and calculated surface energies, the micro-crystal morphologies of three iron oxides are predicted at various oxygen chemical potential. Subsequently, on basis of the data of surface energies, the effect of surface free energies on phase equilibrium of iron oxides nanoparticles are investigated. These results suggest that particle sizes of nanometer have a significant influence on the thermodynamic equilibrium shifting due to their large surfaces energies contributions. This principle can guide people control the phase transition of iron oxides by adjusting surface energies contributions by changing the sizes of particles.
科研通智能强力驱动
Strongly Powered by AbleSci AI