Manipulation of electronic and magnetic properties of M${}_2$C (M=Hf, Nb, Sc, Ta, Ti, V, Zr) monolayer by applying mechanical strains

Abstract

Tuning the electronic and magnetic properties of a material through strain engineering is an effective strategy to enhance the performance of electronic and spintronic devices. Recently synthesized two-dimensional transition metal carbides M${}_2$C (M=Hf, Nb, Sc, Ta, Ti, V, Zr), known as MXenes, has aroused increasingly attentions in nanoelectronic technology due to their unusual properties. In this paper, first-principles calculations based on density functional theory are carried out to investigate the electronic and magnetic properties of M${}_2$C subjected to biaxial symmetric mechanical strains. At the strain-free state, all these MXenes exhibit no spontaneous magnetism except for Ti${}_2$C and Zr${}_2$C which show a magnetic moment of 1.92 and 1.25 ${\mu }_B$/unit, respectively. As the tensile strain increases, the magnetic moments of MXenes are greatly enhanced and a transition from nonmagnetism to ferromagnetism is observed for those nonmagnetic MXenes at zero strains. The most distinct transition is found in Hf${}_2$C, in which the magnetic moment is elevated to 1.5 ${\mu }_B$/unit at a strain of 15%. We further show that the magnetic properties of Hf${}_2$C are attributed to the band shift mainly composed of Hf(5$d$) states. This strain-tunable magnetism can be utilized to design future spintronics based on MXenes.

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Cited by in corpus (8)

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• Electronic and vibrational properties of V${}_2$C-based MXenes: from experiments to first-principles modeling
• Superconductivity of monolayer Mo${}_2$C: the key role of functional groups
• Ferroelectricity in strained Hf${}_2$CF${}_2$ monolayer
• Metal-to-superconductor Transition Induced by Lithium Adsorption on Monolayer 1$T$-Nb${}_2$C
• A Density Functional Theory Study of Magnetic Transition in MnO2 adsorbed Vanadium Carbide (V${}_2$C) MXene