Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Novel MAB phases and insights into their exfoliation into 2D MBenes   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, Hf, V, Nb, Ta, Cr, Mo, W, Mn, Tc),
M$_2$AlB$_2$ (Sc, Ti, Zr, Hf, V, Cr, Mo, W, Mn, Tc, Fe, Rh, Ni),
M$_3$Al$_2$B$_2$ (M = Sc, T, Zr, Hf, Cr, Mn, Tc, Fe, Ru, Ni), M$_3$AlB$_4$ (M =
Sc, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Mn, Fe), and M$_4$AlB$_6$ (M = Sc, Ti,
Zr, Hf, V, Nb, Ta, Cr, Mo). 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.

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The categories of this paper are: mtrl-th
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The categories of this paper are: atom-ph
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The categories of this paper are: cs
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The categories of this paper are: q-fin
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The categories of this paper are: astro-ph
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The categories of this paper are: supr-con
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The categories of this paper are: chao-dyn
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The categories of this paper are: dg-ga
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The categories of this paper are: math-ph
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The categories of this paper are: solv-int
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The categories of this paper are: hep-th
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The categories of this paper are: cmp-lg
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The categories of this paper are: hep-ph
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The categories of this paper are: gr-qc
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The categories of this paper are: hep-ex
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The categories of this paper are: alg-geom