Novel MAB phases and insights into their exfoliation into 2D MBenes

Abstract

Considering the recent breakthroughs in the synthesis of novel two-dimensional (2D) materials from layered bulk structures, ternary layered transition metal borides, known as MAB phases, have come under scrutiny as a means of obtaining novel 2D transition metal borides, so-called MBene. Here, based on a set of phonon calculations, we show the dynamic stability of many Al-containing MAB phases, MAlB (M = Ti, ). By comparing the formation energies of these MAB phases with those of their available competing binary M−B and M−Al, and ternary M−Al−B phases, we find that some of the Sc-, Ti-, V-, Cr-, Mo-, W-, Mn-, Tc-, and Fe-based MAB phases could be favorably synthesized in an appropriate experimental condition. In addition, by examining the strengths of various bonds in MAB phases via crystal orbital Hamilton population and spring constant calculations, we find that the B−B and then M−B bonds are stiffer than the M−Al and Al−B bonds. The different strength between these bonds implies the etching possibility of Al atoms from MAB phases, consequently forming various 2D MB, M 2 B 3 , and M 3 B 4 MBenes. Furthermore, we employ the nudged elastic band method to investigate the possibility of the structural phase transformation of the 2D MB MBenes into graphene-like boron sheets sandwiched between transition metals and find that the energy barrier of the transformation is less than 0.4 eV/atom.

Surface-Related Features Responsible for Cytotoxic Behavior of MXenes Layered Materials Predicted with Machine Learning Approach

“…In addition, the theoretical research methodology based on ML models developed here can be further applied to other types of 2D materials exhibiting complex structure and diverse surface characteristics, such as for example, novel 2D transition metal borides, so called MBenes [69] as well as van der Waals heterostructures [70,71]. We expect that the predictions presented here will facilitate the experimental efforts by providing the information that might accelerate time consuming and expensive cytotoxical experimental studies, by reducing the large number of compounds, and hence, speeding up potential future applications.…”

Defect behavior and radiation tolerance of MAB phases (MoAlB and Fe2AlB2) with comparison to MAX phases

“…In the current study, we consider another class of layered ternary materials labeled as MAB (M = transition metal, A = Al, B = B) phase. Many MAB phases have been predicted theoretically [14] and some of them have already been synthesized (M = Mo, W, Cr, Mn, Fe, and Ru) [1]. In this work we focus on two MAB materials: MoAlB and Fe2AlB2.…”

Lithium nickel borides: evolution of [NiB] layers driven by Li pressure

“…13,14 MXenes are extensively studied due to their attractive thermal, magnetic, mechanical and electric properties. [15][16][17][18][19][20] MBenes were predicted to have similarly fascinating properties [21][22][23][24] but have not yet been obtained experimentally, despite several prominent attempts. [24][25][26][27][28] Recent theoretical investigation of the Li-Ni-B system 29 revealed a new Li-rich layered compound Li 2 NiB, whose structure is derived from RT-LiNiB.…”