Electrical Conduction Characteristic of a 2D MXene Device with Cu/Cr2C/TiN Structure Based on Density Functional Theory

First-Principles Calculate the Stability, Mechanical Properties and Electronic Structure of Carbide MC, M2C and M6C in M50NiL Steel

In this paper, the stability, mechanical properties and electronic structure of carbides in steel were calculated using the first-principles method based on the density functional theory (DFT). Firstly, the MC, M2C, M6C (M = Cr, Mo, V, Fe) carbides models were established. Then, different interphases' lattice constants, formation enthalpy, binding energy and elastic modulus were calculated. The stability, hardness, ductility and anisotropy of each phase were finally analyzed. The results show that these phases are stable, and the stability is closely related to the electron loss ability of its metal elements. The stronger the electron loss ability of its metal elements, the more stable the formed phase. As for MC carbides, MoC has the largest bulk modulus and hardness. As for M2C carbides, the Poisson's ratio of Cr2C is the smallest, and all phases except for Cr2C show toughness and ductility. The anisotropy of M6C carbides is relatively poor.

Nonlinear Optical Modulation Characteristics of MXene Cr2C for 2 μm Pulsed Lasers

MXene materials have shown numerous useful mechanical and electronic properties, and have been found to possess nice potential in the field of optical modulation. Here, we fabricated a MXene Cr₂C saturable absorber by the liquid-phase exfoliation method, and systemically analyzed the surface morphology and nonlinear properties of the Cr₂C sample. Applying the Cr₂C saturable absorber as a Q-switch in a thulium-doped yttrium aluminum perovskite (Tm: YAP) laser, the shortest single pulse was obtained with a width of 602 ns under an absorbed pump power of 3.3 W at a repetition rate of 55 kHz with a T = 1% output coupler. The maximum output power was obtained with a T = 5% output coupler at a repetition rate of 58 kHz. The obtained maximum pulse energy and peak power were 3.96 μJ and 4.36 W, separately, which reveal that the MXene Cr₂C can be applied as a promising modulation material in the near-infrared pulsed lasers.