Intrinsic Structural, Electrical, Thermal, and Mechanical Properties of the Promising Conductor Mo₂C MXene

Abstract

Mo2C, the newly synthesized MXene with a large lateral size and superconductivity property, has attracted increasing interest in material science. Employing first-principles density functional calculations, its intrinsic structural, electrical, thermal, and mechanical properties are investigated in this work. It is found that this MXene is nonmagnetic with a small molar volume. The electrical conductivity is predicted in the order of 106 Ω–1m–1, and its value is significantly influenced by doping. For thermal conductivity, both of the electron and phonon contributions are studied. At room temperature, the Mo2C’s thermal conductivity is determined to be 48.4 Wm–1 K–1, which can be further enhanced by increasing temperature and introducing n-type dopants. The specific heat and thermal expansion coefficient are also assessed, and their values at room temperature are calculated as 290 Jkg–1 K–1 and 2.26 × 10–6 K–1, respectively. Moreover, the thermal contraction of the MXene is found at low temperatures. Under biaxial strains, the elastic modulus is predicted as 312 ± 10 GPa, and the ideal strength is determined to be 20.8 GPa at a critical strain of 0.086. In view of the small molar volume, superhigh electrical conductivity, favorable thermal conductivity, low thermal expansion coefficient, and high mechanical strength, the Mo2C MXene generally merits more widespread applications besides superconductors, such as applying to substrates for other layer materials, and candidate materials for batteries and supercapacitors.

Predicting stable phase monolayer Mo2C (MXene), a superconductor with chemically-tunable critical temperature

“…In general, there are several bands crossing the Fermi level, indicating substantial density of states (DOS) beneficial for higher T c . By further analyzing the projected Previously, a theoretical study by Zha et al 32 reported no magnetization in 1T phase MXene-Mo 2 C. In order to probe the possible magnetism in the 2H phase MXene-Mo 2 C monolayers, we performed spin-polarized calculations in bare and functionalized structures. As can be seen from the electronic density of states (DOS) in Fig.…”

Electronic properties and applications of MXenes: a theoretical review

“…Theoretically, many applications have been proposed for MXenes in electronic [39][40][41][42][43], magnetic [44][45][46][47][48], optical [49,50], thermoelectric [51][52][53][54][55][56], and sensing devices [57], as well as being new potential materials for catalytic and photocatalytic reactions [58][59][60][61][62][63], hydrogen storage media [64,65], and nanoscale superconductivity [66]. Some of MXenes are predicted to be topological insulators with large band gaps involving only d orbitals [67][68][69][70][71].…”

Topological insulators in the ordered double transition metalsM2′M″C2MXenes (M′<

“…The 2D MXenes such as Ti 2 C, V 2 C, Nb 2 C, Ta 2 C, Mo 2 C, Ti 3 C 2 , Nb 4 C 3 have already been synthesized [40,41,46,47]. MXenes are known to have or predicted to have electronic, magnetic, and energy harvesting applications [48][49][50][51][52][53][54][55][56][57][58][59][60][61][62].…”