Eu³⁺-doped bismuth silicate crystal structure and Mulliken charge analysis

Area of Science:

• Materials Science
• Solid State Chemistry
• Computational Materials Science

Background:

• Bismuth silicate (Bi₄Si₃O₁₂ or BSO) is a material with potential applications.
• Understanding doping effects is crucial for tailoring material properties.
• Europium (Eu³⁺) doping is explored to modify BSO characteristics.

Purpose of the Study:

• To investigate the effects of Eu³⁺ doping on the crystal structure and charge distribution of BSO.
• To analyze the impact of varying Eu³⁺ proportions on BSO properties.
• To determine the optimal doping concentration for enhanced covalence.

Main Methods:

• First-principles calculations and density functional theory (DFT) were employed.
• Materials Studio software was used for analysis.
• The virtual crystal approximation method was applied to model doping.

Main Results:

• Eu³⁺ doping, especially at higher concentrations, disrupts the crystal symmetry of BSO.
• Eu-O bond length initially increases then decreases, indicating covalent characteristics, with a minimum at 1/3 doping.
• Bi-O bond length decreases with increasing Eu³⁺ doping, reaching a minimum at 1/3 doping.

Conclusions:

• The study quantifies the structural and electronic changes in BSO due to Eu³⁺ doping.
• Enhanced covalence between Eu-O and Bi-O bonds is observed at a 1/3 Eu³⁺ doping ratio.
• These findings provide insights into the controlled modification of BSO properties through doping.