Enhancing elemental phase-change chalcogenide glass through tailored alloying

Abstract

Phase-change memory is vital in the contemporary nonvolatile memory due to its exceptional storage density and swift read/write speed. Yet, the evolution of artificial intelligence (AI) technology imposes stricter performance demands, necessitating the development of phase-change materials (PCMs) with tailored properties. While doping strategies are commonly employed to devise new PCMs, engineers often resort to the costly "trial-and-error" methodology due to the lack of a comprehensive understanding of how different doping elements influence material properties. Through multi-scale molecular dynamics calculations, this study systematically investigates the alloying mechanisms of various elements with antimony (Sb), thereby advancing the methodological framework for PCM design. Analysis of the amorphous structure, bonding nature, and dynamics of binary Sb-based alloys reveals three categories of dopants: tetrahedral (e.g., Al, Zn, Ga), octahedral (e.g., Cd, In, Sn), and compact polyhedral (e.g., Sc, Ti, Y, Zr). Different dopant groups show unique influences on PCMs: octahedral dopants facilitate faster crystallization kinetics, polyhedral dopants contribute to improved thermal stability, and tetrahedral dopants strike a balance performance. Based on these findings, we predict and evaluate the potential of four new candidate materials for memory applications. Altogether, our research not only deepens the understanding of Sb-based PCMs but also lays the foundation for innovative material design paradigms.