Theoretical prediction of superconductivity in two-dimensional MXenes of molybdenum carbides

Abstract

Theoretically and experimentally, MXenes consisting of Mo and C have aroused much interest for superconductivity in their film and even monolayer forms. Here, based on first-principles calculations, we systematically calculate...

Enhancement of superconductivity in Zr2S2C arising from phonon softening on transition from bulk to monolayer

“…This increased EPC strength enhances the superconducting critical temperature of monolayer to 12.5 K. Our results show that the λ and T c enhanced more than twice in contrast to unstrained monolayer (see table 2 and supplementary figure S7(a)-(f)). By applying strain (1.5%) beyond its maximal amplitude, it exhibits characteristics of charge density wave (CDW) (supplementary figure S8) [58]. As shown in figure S8, an imaginary acoustic phonon mode is observed at high symmetry M-point, same as that of 1T-TiSe 2 [60], so the superlattice of CDW state of monolayer Zr 2 S 2 C may be similar to 1T-TiSe 2 .…”

“…We have applied biaxial tensile strain (ϵ) by changing the lattice parameter, as determined by the formula ϵ = (a-a o )/a o × 100%. Here a o and a are the lattice constants of the unstrained and strained Zr 2 S 2 C monolayer [58]. The band structure calculations show that the monolayer retains its metallic character on the application of strain, and there is an insignificant change in DOS at the Fermi level (shown in supplementary figure S6).…”

First-principles study on structural stabilities, mechanical properties, and biaxial strain-induced superconductivity in Janus MoWC monolayer

“…For instance, a monolayer of 2H-Mo 2 C is projected to be an electron-phonon-mediated superconductor with critical temperature (T c ) of approximately 1.19 K. This T c can be substantially enhanced to 11.79 K by applying a biaxial tensile strain of 10%. 37 Similarly, 2H-Mo 2 N has been identified as a superconductor with T c reaching up to 22 K, and this T c can be further elevated to 37.8 K under biaxial compressive stress. 38 These findings underscore the significant impact of biaxial strain on enhancing the T c of superconductors.…”

Van Hove singularity driven enhancement of superconductivity in two-dimensional tungsten monofluoride (WF)

“…Apart from TMDCs, other 2D compounds based on transition metals, namely transition metal-carbides, nitrides, carbochalcogenides, borides, oxides, hydrides, and halides etc. have also been observed to display superconducting behavior [22][23][24][25][26][27][28][29][30][31].…”