Ab-initio calculations and structural studies of (SiTe)2(Sb2Te3)n (n: 1, 2, 4 and 6) phase-change superlattice films

• Published in: Physica status solidi. PSS-RRL. Rapid research letters Vol. 8; no. 4; pp. 302 - 306
• Main Authors: Saito, Y., Tominaga, J., Fons, P., Kolobov, A. V., Nakano, T.
• Format: Journal Article
• Language: English
• Published: Berlin WILEY-VCH Verlag 01-04-2014; WILEY‐VCH Verlag; Wiley Subscription Services, Inc
• Subjects: Crystal lattices; Crystal structure; density-functional theory; interfaces; Phase transitions; phase-change materials; Substrates; superlattices; tellurides; topological insulators; Topology
• ISSN: 1862-6254; 1862-6270
• DOI: 10.1002/pssr.201409013

(SiTe)2(Sb2Te3)n phase‐change superlattices were investigated theoretically and experimentally. Ab‐initio first principle simulations predicted that the (SiTe)2(Sb2Te3)n structures are stable and possess a Dirac semimetal‐like band structure. Calculation of the Z2 invariant indicated that the structure was topologically nontrivial. (SiTe)2(Sb2Te3)n superlattice structures derived from first‐principles were successfully fabricated on a Si substrate by RF‐magnetron sputtering. XRD and TEM indicated that the superlattice films were highly oriented with the 00X planes of Sb2Te3 and the superlattice normal to the substrate surface. The (SiTe)2(Sb2Te3)n superlattice is suggested as new material system for interfacial phase‐change memory applications. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A (SiTe)2(Sb2Te3)n phase‐change superlattice possesses a Dirac semimetal‐like band structure, where the band gap closes only at the Γ‐point and exhibits a linear dispersion. (SiTe)2(Sb2Te3)n structures derived from first‐principles simulations are successfully fabricated on a Si substrate by RF‐magnetron sputtering, which can be a new material system for interfacial phase‐change memory applications.