Vacancy localization effects on MX2 transition-metal dichalcogenides: A systematic ab initio study

Author(s)

Freire, Rafael L. H. ; de Lima, Felipe Crasto ; Fazzio, Adalberto

• Document type: Journal article
• Source: PHYSICAL REVIEW MATERIALS; v. 6, n. 8, p. 7-pg., 2022-08-09.

Abstract

Two-dimensional transition-metal dichalcogenide (MX2) vacancy formation energetics are extensively investigated. Within an ab initio approach, we study the MX2 systems, with M = Mo, W, Ni, Pd, and Pt, and X = S, Se, and Te. Here we classify that chalcogen vacancies are always energetically favorable over the transition-metal ones. However, for late transition metals Pd 4d, and Pt 5d the metal vacancies are experimentally achievable, bringing up localized magnetic moments within the semiconducting matrix. By quantifying the localization of the chalcogen vacancy states we show that it rules the intra- and intervacancy interactions that establish both the number of vacancy states neatly lying within the semiconducting gap, as well as its electronic dispersion and spin-orbit coupling splitting. Combining different vacancies and phase variability 1T and 1H of the explored systems allows us to construct a guiding picture of the vacancy state localization. (AU)

• FAPESP's process: 17/02317-2 - Interfaces in materials: electronic, magnetic, structural and transport properties
• Grantee: Adalberto Fazzio
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 20/14067-3 - Two-Dimensional Nano-Heteroestructures: DFT Simulations and Machine Learning of Interacting Interfaces
• Grantee: Rafael Luiz Heleno Freire
• Support Opportunities: Scholarships in Brazil - Post-Doctoral