First-principles study of the atomic structure of glassy Ga10Ge15Te75

Abstract First-principles molecular dynamics have been employed to highlight the structural properties of glassy Ga10Ge15Te75 (GGT), a promising disordered system for infrared applications. Our approach relies entirely on the predictive power of density functional theory, in combination with a careful choice of the exchange-correlation functional and the account of van der Waals interactions. Glassy GGT can be viewed as a predominantly tetrahedral network, both with respect to Ge and Ga atoms. Te atoms are mostly twofold coordinated to all combinations of pairs of Ge, Ga or Te atoms. We find little evidence of intermediate range order in the partial structure factors.