Electronic structure and zone-center phonon modes in multiferroic bulk BiFeO3
Electronic structure and zone-center phonon modes in multiferroic bulk BiFeO3
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DOI：
10.1063/1.2908865
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发表时间：
2008-04
影响因子：
3.2
通讯作者：
H. M. Tütüncü;G. P. Srivastava
中科院分区：
文献类型：
--
作者：
H. M. Tütüncü;G. P. Srivastava
我们提出的电子结构和带中心声子模式的菱形R3 c对称性的体BiFeO 3的从头算研究。电子结构用平面波赝势方法研究，电子-电子相互作用用局域自旋密度近似（LSDA）、自旋极化广义梯度近似（σGGA）、LSDA+U和σGGA+U方案处理。结果表明，在合理选择U的旋转不变值的情况下，LSDA+U和σGGA+U方案产生的电子带隙都在光谱值的范围内。计算的电子结构的结果被用来确定通过应用线性响应技术的区域中心声子模式。我们提供了一个更清晰的分析的能量值和偏振特性的拉曼主动模式比目前可从理论和实验研究。
We present ab initio investigations of the electronic structure and zone-center phonon modes in bulk BiFeO3 with rhombohedral R3c symmetry. The electronic structure has been studied using the plane wave pseudopotential method, with electron-electron interaction treated within the local spin density approximation (LSDA), a spin-polarized generalized gradient approximation (σGGA), and the LSDA+U and σGGA+U schemes. It is found that with a reasonable choice of a rotationally invariant value of U both the LSDA+U and σGGA+U schemes produce electronic band gaps in the range of values derived from optical spectroscopy. The computed electronic structure results are utilized to determine the zone-center phonon modes by applying a linear response technique. We provide a clearer analysis of the energy values and polarization characteristics of the Raman active modes than is presently available from theoretical and experimental studies.