Electronic properties of PbCl2 and PbBr2 using Compton scattering technique

Area of Science:

• Solid State Physics
• Computational Materials Science
• Quantum Chemistry

Background:

• Lead halides like PbCl2 and PbBr2 are important materials with applications in various fields.
• Understanding their electronic structure and properties is crucial for material design.

Purpose of the Study:

• To experimentally determine electron momentum densities of PbCl2 and PbBr2.
• To theoretically investigate their electronic band structure, density of states, and Compton profiles.
• To correlate theoretical findings with experimental data and explain luminescence properties.

Main Methods:

• Experimental measurement of electron momentum densities using 661.65 keV gamma-rays from a 137Cs source.
• Theoretical calculations using linear combination of atomic orbitals (LCAO) within Hartree-Fock (HF) and density functional theory (DFT).
• Full potential linearized augmented plane wave (FP-LAPW) method for energy band computations.

Main Results:

• Experimental electron momentum densities were obtained for PbCl2 and PbBr2.
• Theoretical calculations provided insights into energy bands, density of states, and Compton profiles.
• Mulliken's population analysis indicated PbCl2 exhibits higher covalency than PbBr2.
• HF and DFT Compton profiles showed similar deviations from experimental data.

Conclusions:

• The study establishes a correlation between theoretical calculations and experimental measurements of electron momentum densities.
• The observed covalency difference between PbCl2 and PbBr2 is supported by theoretical analyses.
• Luminescence properties of these lead halides can be explained through their electronic band structure and density of states.