Metal to semiconductor transition in metallic transition metal dichalcogenides

Abstract

Stability, structural, and magnetic phase diagrams of ternary ferromagnetic 3d-transition-metal clusters with five and six atoms J. Chem. Phys. 134, 054101 (2011); 10.1063/1.3533954 Thickness dependence of ferromagnetic-and metal-insulator transition in thin EuO filmsWe report on tuning the electronic and magnetic properties of metallic transition metal dichalcogenides (mTMDCs) by 2D to 1D size confinement. The stability of the mTMDC monolayers and nanoribbons is demonstrated by the larger binding energy compared to the experimentally available semiconducting TMDCs. The 2D MX 2 (M ¼ Nb, Ta; X ¼ S, Se) monolayers are non-ferromagnetic metals and mechanically softer compared to their semiconducting TMDCs counterparts. Interestingly, mTMDCs undergo metal-to-semiconductor transition when the ribbon width approaches to $13 Å and $7 Å for zigzag and armchair edge terminations, respectively; then these ribbons convert back to metal when the ribbon widths further decrease. Zigzag terminated nanoribbons are ferromagnetic semiconductors, and their magnetic properties can also be tuned by hydrogen edge passivation, whereas the armchair nanoribbons are non-ferromagnetic semiconductors. Our results display that the mTMDCs offer a broad range of physical properties spanning from metallic to semiconducting and non-ferromagnetic to ferromagnetic that is ideal for applications where stable narrow bandgap semiconductors with different magnetic properties are desired. V C 2013 AIP Publishing LLC. [http://dx.

Charge transfer vs. dimensionality: what affects the transport properties of ferecrystals?

“…A sequence that resembles the targeted compounds is evaporated onto a silicon substrate with the correct stoichiometric and thickness ratio of the final compounds. (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20) were synthesized using similar conditions. For each sample (([SnSe] 1.16 ) m (NbSe 2 ) 2 ), m layers of SnSe (m = 1-20) and two layers of NbSe 2 were repeatedly deposited until a thickness of ~ 50 nm was reached.…”

“…2,10,11 The change in dimensionality from three to two has been shown to lead to changes in interlayer coupling, degree of quantum confinement and electronic structures. 13,14 There are also reports where ultra-thin films maintain bulk properties, for example the charge density wave (CDW) transition is still observed in nanosheets of metallic VSe 2 . NbX 2 and TaX 2 , which show a CDW and a superconducting transition in bulk, have been reported to exhibit semiconducting properties as nanosheets.…”

Magnetic properties of transition metal dichalcogenides-Fe/Ir(111) interfaces from first principles

“…In addition, the spin-valve effect was evidenced in experiments performed for a monolayer MoS 2 acting as a nonmagnetic spacer in NiFe/MoS 2 /NiFe heterostructures [31] and a similar spin-dependent transport behavior was revealed for Fe 3 O 4 /MoS 2 /Fe 3 O 4 magnetic tunnel junctions [32]. From a theoretical point of view, several studies focused especially on the electronic properties of the intrinsic magnetic VS 2 and VSe 2 monolayers [33,34], in TMD nanoribbons [35,36], in hydrogenated [37] and fluorinated [38] single TMD layers, and in TMD monolayers doped with transition metal atoms [39][40][41] or strain-induced ones [42][43][44]. On the other hand, less attention was focused on the properties of TMDs on magnetic substrates [45][46][47][48][49][50] that can serve, for instance, as electrodes in spintronic devices [51].…”

Two-Dimensional Atomic Crystals: Paving New Ways for Nanoelectronics

“…However, great efforts have been made to fabricate these materials on a large scale because of their fundamental properties, including electrical, optical, mechanical, thermal and chemical. [145][146][147][148] Interestingly, Staley et al observed superconductivity in two molecular layer NbSe 2 flakes. 145 An onset superconducting transition temperature (T c ) was up to 2.5 K. Similar phenomena were achieved in a few molecular layer NbSe 2 flakes field-effect transistors.…”