Grain rotation and coupled grain boundary motion in two-dimensional binary hexagonal materials

Atomic ordering and phase separation in lateral heterostructures and multijunctions of ternary two-dimensional hexagonal materials

“…Among them the binary honeycomb phase, with each of its triangular sublattices occupied by A or B component separately, corresponds to the lattice structure of monolayer h-BN or the in-plane projection of trigonal prismatic 2H phase of MX 2 TMDs, while the phase with triangular A(B) and honeycomb B(A) sublattices is the in-plane version of octahedral 1T phase of TMDs. This PFC model has been used to identify and predict the defect structure, energy, and dynamics of h-BN grain boundaries [30,36], with results consistent with experiments and atomistic calculations (DFT or MD), and to examine graphene/h-BN and h-BN/h-BN heterostructures and bilayers [33,34] as well as thermal transport of h-BN monolayers [35]. It is important to note that the model can also be applied to a wider range of 2D compound materials with binary honeycomb lattice, including the atomically thin MX 2 TMDs of 2H phase (e.g., M = Mo, W, Nb, X = S, Se; MoTe 2 , TaS 2 ) and transition metal chalcogenides of 1H phase (e.g., FeSe) [37].…”

“…A starting point of our modeling of 2D heterostructural growth is the understanding of individual grain growth dynamics, based on some basic mechanisms and outcomes revealed in the study of binary AB grains [30,36]. As shown in Fig.…”

“…The ternary density-field model introduced here is based on the PFC approach which is able to resolve microscopic crystalline details of the material system and simulate dynamical processes at large diffusive timescales [19][20][21][22][23]. This method has been used in a wide range of applications such as the study of binary and multicomponent alloy systems [24][25][26][27] and 2D hexagonal materials [28][29][30][31][32][33][34][35][36]. The ternary PFC model developed in this work is for modeling the mixture or alloying of AB and CB type 2D material compounds, and is applied to examining the properties of 2D monolayers subjected to vertical confinement when deposited on a substrate (as in the epitaxial growth of real materials).…”

Moiré patterns and inversion boundaries in graphene/hexagonal boron nitride bilayers

“…[15,17] a binary PFC model with sublattice ordering was developed, and was used to examine various types of grain boundaries and defect core structures in hBN monolayers, with results shown to be in good agreement with experiments and other theoretical studies. These PFC models have been applied and extended to study various other structural and dynamical properties of 2D materials, such as grain rotation and coupled motion in graphene and hBN [18], g/hBN lateral heterostructures [19], and ternary 2D hexagonal materials and in-plane TMD/TMD heterostructures and multijunctions [20]. However, these models were strictly 2D and did not allow for out-of-plane variations.…”

Grain Coarsening of a Powder Metallurgical High‐Speed Steel After Sliding Wear

“…[ 7 ] Grain rotation and grain boundary migration caused by plastic deformation are the main factors involved in grain growth in both 2D and 3D materials. [ 8 ] The nanotwin also plays a key role in changing local grain orientation and dissociating boundaries of nanograins, which helps the grain growth. [ 9 ] Apart from plastic deformation, grain coarsening assisted by thermal effects will be involved when rising to a certain temperature.…”