Ab initio study of the electronic and optical properties of sillimanite (Al2SiO5) crystal

Author(s)

Cano, Nilo F. ^{[1, 2]} ; Watanabe, Shigueo ^[1]

Affiliation

^[1] Univ Sao Paulo, Inst Phys, BR-05508090 Sao Paulo - Brazil

^[2] Univ San Agustin Arequipa, Profess Sch Phys, Arequipa - Peru

• Document type: Journal article
• Source: Optical Materials; v. 33, n. 11, p. 1813-1816, SEP 2011.
• Web of Science Citations: 2

Abstract

Ab initio calculations based on the density functional theory (DFT) are used to investigate the electronic and optical properties of sillimanite. The geometrical parameters of the unit cell, which contain 32 atoms, have been fully optimized and are in good agreement with the experimental data. The electronic structure shows that sillimanite has an indirect band gap of 5.18 eV. The complex dielectric function and optical constants, such as extinction coefficient, refractive index, reflectivity and energy-loss spectrum, are calculated. The optical properties of sillimanite are discussed based on the band structure calculations. It is shown that the O-2p states and Al-3s, Si-3s states play the major role in optical transitions as initial and final states, respectively. (C) 2011 Elsevier B.V. All rights reserved. (AU)

• FAPESP's process: 07/08008-0 - Intrinsic defects in silicate crystals: numerical calculations in the case of diopside
• Grantee: Nilo Francisco Cano Mamani
• Support Opportunities: Scholarships in Brazil - Post-Doctoral