Electronic and optical properties of ceramic Sc2O3 and Y2O3: Compton spectroscopy and first principles calculations

• Published in: The Journal of physics and chemistry of solids 2016-05, Vol.92, p.53-63
• Main Authors: Ahuja, Babu Lal, Sharma, Sonu, Heda, Narayan Lal, Tiwari, Shailja, Kumar, Kishor, Meena, Bhoor Singh, Bhatt, Samir
• Format: Article
• Language: English
• Subjects: Ceramic materials; Compton scattering; Density functional theory; Electronic structure
• ISSN: 0022-3697; 1879-2553
• DOI: 10.1016/j.jpcs.2016.01.016

We present the first-ever experimental Compton profiles (CPs) of Sc2O3 and Y2O3 using 740 GBq 137Cs Compton spectrometer. The experimental momentum densities have been compared with the theoretical CPs computed using linear combination of atomic orbitals (LCAO) within density functional theory (DFT). Further, the energy bands, density of states (DOS) and Mulliken's population (MP) data have been calculated using LCAO method with different exchange and correlation approximations. In addition, the energy bands, DOS, valence charge density (VCD), dielectric function, absorption coefficient and refractive index have also been computed using full potential linearized augmented plane wave (FP-LAPW) method with revised functional of Perdew–Becke–Ernzerhof for solids (PBEsol) and modified Becke Johnson (mBJ) approximations. Both the ab-initio calculations predict wide band gaps in Sc2O3 and Y2O3. The band gaps deduced from FP-LAPW (with mBJ) are found to be close to available experimental data. The VCD and MP data show more ionic character of Sc2O3 than Y2O3. The ceramic properties of both the sesquioxides are explained in terms of their electronic and optical properties. [Display omitted] •Reported Compton profile (CP) measurements on Sc2O3 and Y2O3.•Interpreted CP data in terms of LCAO-DFT calculations.•Calculated electronic and optical properties using LCAO and FP-LAPW schemes.•Discussed bonding using valence–charge–density and MP data.