[1] Janowitz C, Scherer V, Mohamed M, et al. Experimental electronic structure of In2O3 and Ga2O3[J].New Journal of Physics,2011,13(8): 1-15.
[2] Takakura K, Koga D, Ohyama H, et al. Evaluation of the crystalline quality of β-Ga2O3 films by optical absorption measurements[J].Physica B Condensed Matter,2009,404(23-24): 4854-4857.
[7] Laugier M T. Indentation cracking in ceramics and cermets[J].Proceedings of the 2nd international conference on science of hard materials,1986: 449-455.
[10] Zhang T H, Feng Y H, Yang R, et al. A method to determine fracture toughness using cube-corner indentation[J].Scripta Materialia,2010,62(4): 199-201.
[11] Yang R, Zhang T H, Jiang P, et al. Experimental verification and theoretical analysis of the relationships between hardness, elastic modulus, and the work of indentation[J].Applied Physics Letters,2008,92: 1-4.
[12] Yang R, Zhang T H, Feng Y H. Theoretical analysis of the relationships between hardness, elastic modulus, and the work of indentation for work-hardening materials[J].Journal of Materials Research,2010,25(11): 2072-2077.
[13] Johnson K L. Contact mechanics[D].Cambridge: Cambridge University Press,1985.