FisMat2017 - Submission - View

Abstract's title: A first-principles study of liquid and amorphous phases of the In2Te3 compound
Submitting author: Daniele Dragoni
Affiliation: Universita' di Milano - Bicocca
Affiliation Address: Via R. Cozzi 55
Country: Italy
Oral presentation/Poster (Author's request): Oral presentation
Other authors and affiliations: Marco Bernasconi (Universita' di Milano - Bicocca), Silvia Gabardi (Universita' di Milano - Bicocca)
Abstract

Phase-change materials have been widely used in electronic industry thanks to their ability to rapidly and reversibly switch from amorphous to crystalline phase. In particular, being a good compromise between speed of crystallization and stability of the amorphous phase, Ge2Sb2Te5 proved to be an excellent material for optical-storage devices such as DVD and non-volatile phase-change memories (PCMs).  Despite its success though, the crystallization temperature of this compound ~393 K is too low for applications in automotive where higher working temperatures are required. Hence, the necessity to find new materials which crystallize at higher temperatures. Along this direction, the ternary system In-Sb-Te has been proposed as a possible alternative candidate. In order to better understand the properties of the ternary system we decided first to take under consideration the In-Te compound, focusing our attention on the In2Te3 composition.
Using molecular dynamics based on density functional theory we perform a comprehensive study of the structural, vibrational and electronic properties of the liquid and of the glass quenched from the melt.  We compare results obtained with BLYP and BLYP+D3, rVV10 which also include van der Waals interactions. We observe that all the models show a mostly tetrahedral environment for In atoms and a mostly pyramidal configuration for Te atoms, similarly to the local geometry of the crystalline phase.