Tensile Mechanical Behavior and the Fracture Mechanism in Monolayer Group-III Nitrides XN (X= Ga, In): Effect of Temperature and Point Vacancies

Abstract

In this study, we have thoroughly investigated the tensile mechanical behavior of monolayer XN (X = Ga, In) using molecular dynamics simulations. The effects of temperature (100 to 800 K) and point vacancies (PVs, 0.1 to 1%) on fracture stress, strain, and elastic modulus of GaN and InN are studied. The effects of edge chiralities on the tensile mechanical behavior of monolayer XN are also explored. We find that the elastic modulus, tensile strength, and fracture strain reduce with increasing temperature. The point defects cause the stress to be condensed in the vicinity of the vacancies, resulting in straightforward damage. On the other hand, all the mechanical behaviors such as fracture stress, elastic modulus, and fracture strain show substantial anisotropic nature in these materials. To explain the influence of temperature and PVs, the radial distribution function (RDF) at diverse temperatures and potential energy/atom at different vacancy concentrations are calculated. The intensity of the RDF peaks decreases with increasing temperature, and the presence of PVs leads to an increase in potential energy/atom. The current work provides an insight into adjusting the tensile mechanical behaviors by making vacancy defects in XN (X = Ga, In) and provides a guideline for the applications of XN (X = Ga, In) in flexible nanoelectronic and nanoelectromechanical devices.

Crystal orientation-dependent tensile mechanical behavior and deformation mechanisms of zinc-blende ZnSe nanowires

“…This form of RDF function with increasing temperature thus denotes the cause of mechanical strength loss at high temperatures, which is consistent with previous research 17 . Deformation mechanisms at different strain values can be used for quantitative and qualitative explanations of mechanical behavior [76][77][78][79] . Firstly, to explore the effects of crystal orientations, the stress propagation and deformation pattern of ZnSe NWs at room temperature for three different orientations 1c) is large compared to the [100] direction, and hence, a lesser extent of uniaxial tensile strain compared to the [100] direction facilitates the crack initiation.…”

Anisotropic crystal orientations dependent mechanical properties and fracture mechanisms in zinc blende ZnTe nanowires

“…We have also estimated the RDF, g(r), at three discrete temperatures to qualitatively elucidate the temperatureinduced mechanical performance. [61][62][63] The RDFs of Zn-Zn, Zn-Te, and Te-Te pairs in the ZnTe system as a function of temperature are illustrated in Fig. S2a-c (ESI †).…”

Bandgap engineering and modulation of thermodynamic, and optical properties of III-N monolayers XN (X = In, Ga & Al) by mutual alloying

“…For this system, the electronic bandgap variation with concentration 'x' may play an important role in realizing numerous optoelectronic devices [26][27][28]. In comparing these bulk group-III nitrides materials and their alloys, materials with diluted anion III-nitride are not explored much [20,21,[29][30][31]. Mostly, this problem is observed in the small structures of supercells due to the localization effect of wavefunctions [32].…”