Electronic structure of aluminum oxide: ab initio simulations of α and γ phases and comparison with experiment for amorphous films

¹ Institute of Semiconductor Physics, Siberian Branch of the Russian Academy of Sciences, Academician Lavrentiev Ave. 13, 630090 Novosibirsk, Russia
² Boreskov Institute of Catalysis, Siberian Branch of the Russian Academy of Sciences, Academician Lavrentiev Ave. 5, 630090 Novosibirsk, Russia

Corresponding authors: timson@isp.nsc.ru grits@isp.nsc.ru vvk@catalysis.nsk.su

Received: 28 May 2010
Accepted: 10 August 2010
Published online: 30 November 2010

Abstract

The electronic structure of γ-Al₂O₃ and α-Al₂O₃ has been investigated by means of the density functional theory. A comparison of the calculation results with experimental data for amorphous alumina films is also presented. The electronic structure is described in terms of band structure and density of states. It has been found that γ-Al₂O₃ have similar electronic structure with α-Al₂O₃ and amorphous Al₂O₃. Effective electron masses in γ-Al₂O₃ as well as in α-Al₂O₃ equal to ≈ 0.4 m₀ that is in a good agreement with the experimentally found tunnel electron mass in amorphous Al₂O₃. The heavy holes in both alumina crystals are explained by the valence band top forming by O 2p_π nonbonding orbitals.