Modulating the thermal and structural stability of galleneneviavariation of atomistic thickness

Abstract

Using ab initio molecular dynamics, we show that a recently discovered form of 2D Ga—gallenene—exhibits highly variable thickness dependent properties.

Structural and electronic changes in Ga–In and Ga–Sn alloys on melting

“…An exchangecorrelation functional at the generalised gradient approximation level was employed: Perdew-Burke-Ernzerhof for solids (PBEsol). 39 This functional represented an acceptable balance between accuracy and computational tractability, and has previously been used to accurately describe the melting behaviour of Ga materials 23,24 as well as other metallic systems such as Na, Mg and Al. 40 A plane-wave basis set was used to represent valence electrons, with a kinetic energy cut-off of 350 eV.…”

“…2 Specific heat curves for hexa-layer Ga-In (red) and Ga-Sn (blue) systems, with peaks indicating phase transitions at 386 K and 349 K, respectively. These curves are compared to pure hexa-layer Ga which as previously been found to have a melting point of 433 K. 23 Fig. 1 Structures of hexa-layer Ga randomly doped with 7.8 at% In viewed from (a) the y-direction and (b) the z-direction.…”

“…18 Whereas other work suggests the low temperature melting is associated with the existence of dimeric Ga 2 structures. 19 There has also been significant recent interest in atomically thin 2D structures of Ga, [20][21][22] which are shown to demonstrate differing thermal stability depending on thickness, 19,23,24 and often melt at higher temperatures than the bulk.…”

Single-Element 2D Materials beyond Graphene: Methods of Epitaxial Synthesis

“…A characteristic feature of gallenene is the covalent bond between adjacent two-dimensional layers, in contrast to other 2D materials, such as, for example, graphite or transition metal dichalcogenides, in which the layers are linked together by weak van der Waals forces. Due to this, the gallium layers demonstrate significantly higher temperature stability [101,102].…”

“…For instance, a material such as borophene is predicted to serve as an effective energy storage and also may form nanotubes analogous to those of graphene, which may have even higher electrical conductivity that suggests the possibility of their use as contacts and interconnections in nanodevices [91]. Multi-layer gallenene structures are expected to have significantly higher temperature stability than bulk material [102]. Strained layers of stanene have potential as possible room-temperature device applications due to a very wide bandgap induced by elastic strains [42,43].…”