通讯机构：
[Deng, Xiaohui] H;Hengyang Normal Univ, Dept Phys & Elect Informat Sci, Hengyang 421008, Peoples R China.
关键词：
Thermodynamic properties;Quasiharmonic approximation;Lattice dynamics;Density functional theory
摘要：
The finite-temperature density functional theory and the quasiharmonic approximation are adopted to investigate thermodynamics properties of hexagonal osmium. By varying lattice volume, the anharmonic effect is part considered in present work. Phonon frequencies calculations are performed from density functional perturbation theory (DFPT). By fitting the total free energy (including both electronic and vibrational parts) to equation of states at different temperatures, some classical thermodynamic quantities and their pressure and temperature dependences are investigated systematically. The results are in good agreement with the available experimental and theoretical data.Research Highlights► The finite-temperature DFT and QHA were adopted. ► Thermodynamic properties were investigated systematically. ► CV reaches a constant (∼3 R) with T approaching to the ΘD. ► CP shows an approximate linear behavior beyond the experimental ΘD. ► The temperature dependence on γ is small.
期刊：
JOURNAL OF PHYSICS-CONDENSED MATTER,2010年22(20):205501 ISSN：0953-8984
通讯作者：
Deng, Xiaohui
作者机构：
[Wang, Wenwei; Deng, Xiaohui; Zhang, Dengyu] Hengyang Normal Univ, Dept Phys & Elect Informat Sci, Hengyang 421008, Peoples R China.;[Lu, Wei] Hong Kong Polytech Univ, Dept Appl Phys, Kowloon, Hong Kong, Peoples R China.;[Fan, Bingbing] City Univ Hong Kong, Dept Phys & Mat Sci, Hong Kong, Hong Kong, Peoples R China.;[Fan, Bingbing] City Univ Hong Kong, COSDAF, Hong Kong, Hong Kong, Peoples R China.;[Fan, Bingbing] Zhengzhou Univ, Sch Mat Sci & Engn, Zhengzhou, Henan, Peoples R China.
通讯机构：
[Deng, Xiaohui] H;Hengyang Normal Univ, Dept Phys & Elect Informat Sci, Hengyang 421008, Peoples R China.
摘要：
The first-principles spin polarization method is used to investigate the magnetic properties of graphite boron nitride (g-BN) sheet induced by Fe doping. We find that a nitrogen or boron atom substituted by Fe can induce a magnetic moment. From standard Mulliken population analysis, we also find that the magnetic moment is mainly dominated by Fe 3d states. Using Heisenberg exchange coupling theory, we study the exchange coupling mechanisms by constructing two-Fe centers in g-BN. The results show the presence of relatively strong exchange coupling for two-Fe substituted two-B atoms and the coupling is ferromagnetic. For the case of two-Fe substituted two-N atoms, the coupling is antiferromagnetic and the exchange coupling is very weak. The paper enriches recent molecular magnetic investigations.
