Atomic and Electronic Structure of LaAlO₃ and LaAlO₃:Mg from First-Principles Calculations

Abstract:

In the present paper, the lattice structure, band structure and density of state of LaAlO3 and LaAlO3:Mg are calculated by first-principle method based on density functional theory. Firstly, we select the different cutoff energy and k-point grid in the calculations, and obtain the most stable geometry structure of single crystal LaAlO3. The calculated lattice parameters are a=b=5.441 Å, c=13.266 Å, which matches with experimental values. To deeply understand the electronic structure of LaAlO3, a 2×1×1 super-cell structure is established and the doping concentration of Mg at Al sites is 25%. From the band structure and density of states, it can be seen that LaAlO3 has a direct band gap Eg=3.6 eV. However, LaAlO3:Mg has a larger band gap Eg=3.89 eV and the Fermi level enters into the valence band, which indicates the holes are introduced. The calculated results show that the conductivity of LaAlO3:Mg is better than pure LaAlO3, which is in good agreement with experimental results.

• Periodical: Advanced Materials Research (Volumes 79-82)
• Pages: 1257-1260
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.79-82.1257
• Online since: August 2009
• Authors: Li Guan, Li Tao Jin, Wei Zhang, Qiang Li, Jian Xin Guo, Bo Geng, Qing Xun Zhao, Bao Ting Liu
• Keywords: Doping, Electronic Structure, First-Principle, LaAlO₃

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