研究目的
To investigate the effect of magnesium doping on the structural and optical properties of CaTiO3 using density functional theory calculations.
研究成果
Mg doping in CaTiO3 increases the band gap from 1.84 eV to 1.92 eV, shifts the Fermi level towards the valence band, and enhances optical properties such as absorption edge (blue shift from 2.1 eV to 2.5 eV) and refractive index (increase from 2 to 2.4). This makes Mg-doped CaTiO3 a promising candidate for optoelectronic devices.
研究不足
The study is purely computational and based on DFT approximations (e.g., GGA), which may not fully capture experimental realities. The doping concentration is low (x=0.112), and effects at higher concentrations or other doping sites are not explored. No experimental validation is provided.
1：Experimental Design and Method Selection:
The study uses first-principles calculations based on density functional theory (DFT) with the CASTEP code, employing ultra-soft pseudo-potentials (USP) and the generalized gradient approximation (GGA-PBE) for exchange-correlation. A 2x2x1 supercell of CaTiO3 with 42 atoms is used, and Mg is doped by replacing Ca atoms at a concentration of x=0.112. Geometry optimization is performed using the Birch-Murnaghan equation of state.
2：Geometry optimization is performed using the Birch-Murnaghan equation of state.
Sample Selection and Data Sources:
2. Sample Selection and Data Sources: The ideal cubic structure of CaTiO3 (space group pm-3m) is selected for stability at room temperature. No experimental samples are used; all data are computational.
3：List of Experimental Equipment and Materials:
Computational software CASTEP is used; no physical equipment or materials are mentioned.
4：Experimental Procedures and Operational Workflow:
The lattice parameters are optimized, followed by calculations of electronic band structure, density of states (TDOS and PDOS), and optical properties (dielectric function, refractive index, absorption, reflectivity, loss function). A Monkhorst-Pack grid of 2x2x1 is used for Brillouin zone sampling.
5：Data Analysis Methods:
Results are analyzed by comparing pure and doped systems, focusing on changes in band gap, Fermi level shift, and optical property variations. Graphs and figures are used for visualization.
独家科研数据包，助您复现前沿成果，加速创新突破
获取完整内容
