Nonpolar 1T-to-1T' order-disorder transition in a MoS2 monolayer

Ma, Xue1; Fan, Ningbo1; Zhao, Jinzhu2,3,4; Xu, Bin1

2023-11-01

10.1103/PhysRevB.108.184101

PHYSICAL REVIEW B   影响因子和分区

2469-9950

2469-9969

Finding two-dimensional (2D) materials with ferroelectricity is of great interests towards polarization-related applications and nanosized devices. Despite much theoretical efforts that predict the existence of novel 2D ferroelectrics, only a small portion have been realized in experiments. The well-known 2D transition-metal dichalcogenide molybdenum disulfide (MoS2) monolayer was predicted to have a ferroelectric d1T polymorph resulting from condensation of soft phonons from the centrosymmetric 1T phase. However, experiments mostly obtain a nonpolar monoclinic 1T ' phase, whereas the d1T phase has not been observed. In this study, we use various first-principles techniques, including density-functional theory total-energy calculations, ab initio molecular dynamics, and the temperature-dependent effective potential method to show that the nonpolar 1T' phase is thermodynamically more stable than the d1T phase. Furthermore, the 1T phase at high temperature is averaged among degenerate 1T' structures, and the 1T-to-1T' transition upon cooling is predicted to be of first order with a strong order-disorder character. Effect of strain on the stable structure and the likely ground state of other MoX2 (X = Se, Te) monolayers are also discussed.

SCI ; EI

英语

其他

National Natural Science Foundation of China[12274145] ; Guangdong Provincial University Sci- ence and Technology Program[2023KTSCX029]

Materials Science ; Physics

Materials Science, Multidisciplinary ; Physics, Applied ; Physics, Condensed Matter

WOS:001096831300001

AMER PHYSICAL SOC

20234715085875

Density functional theory ; Ferroelectricity ; Ground state ; Layered semiconductors ; Molecular dynamics ; Molybdenum disulfide ; Transition metals

Metallurgy and Metallography:531 ; Electricity: Basic Concepts and Phenomena:701.1 ; Semiconducting Materials:712.1 ; Physical Chemistry:801.4 ; Inorganic Compounds:804.2 ; Probability Theory:922.1 ; Atomic and Molecular Physics:931.3 ; Quantum Theory; Quantum Mechanics:931.4

PHYSICS

Web of Science

1.Soochow Univ, Inst Theoret & Appl Phys, Sch Phys Sci & Technol, Jiangsu Key Lab Thin Films, Suzhou 215006, Peoples R China
2.South China Normal Univ, Guangdong Basic Res Ctr Excellence Struct & Fundam, Sch Phys, Guangdong Prov Key Lab Quantum Engn & Quantum Mat, Guangzhou 510006, Peoples R China
3.South China Normal Univ, Frontier Res Inst Phys, Guangdong Hong Kong Joint Lab Quantum Matter, Guangzhou 510006, Peoples R China
4.Southern Univ Sci & Technol, Ctr Computat Sci & Engn, Shenzhen 518055, Peoples R China

Ma, Xue,Fan, Ningbo,Zhao, Jinzhu,et al. Nonpolar 1T-to-1T' order-disorder transition in a MoS2 monolayer[J]. PHYSICAL REVIEW B,2023,108(18).

Ma, Xue,Fan, Ningbo,Zhao, Jinzhu,&Xu, Bin.(2023).Nonpolar 1T-to-1T' order-disorder transition in a MoS2 monolayer.PHYSICAL REVIEW B,108(18).

Ma, Xue,et al."Nonpolar 1T-to-1T' order-disorder transition in a MoS2 monolayer".PHYSICAL REVIEW B 108.18(2023).