Structural evolution of free-standing 2D silicon carbide upon heating
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THE EUROPEAN PHYSICAL JOURNAL D
Regular Article
Structural evolution of free-standing 2D silicon carbide upon heating Tue Minh Le Nguyen1,2 , Vo Van Hoang1,2 , and Hang T.T. Nguyen1,2,a 1
2
Laboratory of Computational Physics, Faculty of Applied Science, Ho Chi Minh City University of Technology (HCMUT), Ho Chi Minh City, 268 Ly Thuong Kiet Street, District 10, Ho Chi Minh City, Vietnam Vietnam National University Ho Chi Minh City, Linh Trung Ward, Thu Duc District, Ho Chi Minh City, Vietnam Received 21 February 2020 / Received in final form 23 March 2020 Published online 9 June 2020 c EDP Sciences / Societ`
a Italiana di Fisica / Springer-Verlag GmbH Germany, part of Springer Nature, 2020 Abstract. Two-dimensional Silicon Carbide (2D SiC) model is studied via molecular dynamics simulation to observe the structural evolution upon heating. A model contains 11040 atoms interacting via Vashishta potentials. The model is heated up from 50 K to 4500 K in order to observe the changes in structures during heating process. The melting point of free-standing 2D SiC is defined to be around 4050 K by temperature dependence of the heat capacity. The Lindemann criterion for 2D case is calculated and used to classify the behaviors of the liquid like and solid like atoms. The atomic mechanism of structural evolution upon heating is analyzed based on the occurrence/growth of liquid like atoms the average coordination number the ring statistics as well as the angular distributions.
1 Introduction 2D materials have been studied both theoretically and experimentally in the recent years. Some typical materials can be classified as graphene and graphene-like materials (Si, Ge, BN. . .) which can be used as a substrate for graphene synthesis [1–8]. In addition hybridization of graphene with other 2D materials to design electronic components has also been studied intensively [9–13]. Moreover the synthesis of carbon with other elements to create new materials is carried out. For instance the combinations of B–N and C–C bonds tend to separate the BCN heterostructures into a new structure consisting of hybridized phases h-BN and graphene (hBNC) [14,15]. This would give a new method of controlling the physical properties of graphene-based structures. Regarding Si and C synthesis, Li et al. reported that 2D Si–C compounds have a high thermal stability such that the Si2 C3 -I and SiC3 -I sheets can preserve their planar geometries below 3500 K while the SiC4 -I sheet can sustain up to 4000 K of planar structure [16]. In contrast SiC can be considered as one of the promising candidates to solve the heat-sink problem which may play an important role in metallic materials used for electronic devices [17–19]. The main idea of this solution is to use composite materials instead of metals as the matrix and ceramics such as SiC as reinforcement [20–23]. The reasons of choosing SiC are due to its unique physical and chemical properties such as high thermal conductivity high performance with respect to low price and suitable coefficient of the th
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