Thermoelectric, spin-dependent optical and quantum transport properties of 2D half-metallic Co₂Se₃

Abstract

In this paper, the thermoelectric, spin-dependent optical and quantum transport properties of two-dimensional(2D) Co2Se3 monolayer are investigated using first principle calculations. The stability of Co2Se3 monolayer is confirmed by energy-cohesive...

Emerging 2D Cobalt Telluride (CoxTey): from Theory to Applications

“…Figure 3a shows the current-voltage (I-V) curves of CoTe fieldeffect transistor from 5 to 300 K. The nonlinear I-V curves exhibit reduced current density at lower temperature. A negative gate voltage (Figure 3b) increases the channel current, suggesting the p-type semiconductor of CoTe nanostructure prepared from the [ 32] 1: semiconducting (nano-size or quantum dot) [ 96] ; 2: metallic, 1.8×10 6 S/m (film) [98] 1: semiconducting [34] ; 2: metallic [ 76] nonmetallic [ 57] saturation magnetization 37.38 emu/g [33] 0.38 emu [ 58] weak ferromagnetism [34,76] ∼10 emu/g [ 57] 7.52 emu/g [ 81] paramagnetic [ 58,83] 13.4 emu/g [ 83] others 1: low overpotential [ 16] ; 2: ferrimagnetic [ 81] 1: Dirac fermiology [ 24] ; 2: temperature-dependent emission [ 30] ;…”

“…Similarly, intense progress in expanding the border of Co x Te y in the aspects of piezoelectric and electronic properties was also made in the last decade. [23,24,76,77] In this section, the mechanism, reinforcement and advance of Co x Te y 's properties, especially in 2D limit, will be individually overviewed.…”

“…3: anisotropic bulk dispersion [76] ; 4: piezo-/tribo-electric [96] ; 5: quantum criticality [ 99] ; 6: nonlinear hall effect [ 100] 1: piezoelectric [ 34] ; 2: magnetocrystalline anisotropy [ 34] ; present applications 1: photocatalyst [18] ; 2: supercapacitor [ 55] ; 3: electrocatalyst [74] ; 4: sensing [84] 1: supercapacitors [ 46] ; 2: nanogenerators, energy harvesting devices [ 96] ; 3: magnetoresistance [98] energy harvestings [ 34,76] 1: water splittings [16] ; 2: energy storages [ 20] potential applications solvothermal method. From the hysteresis loops (M-H) curves (Figure 3c), the coercivity (H c ) decreases exponentially with elevated temperature from 10 to 300 K. The calculated saturation moment of CoTe was ≈0.2 μ B Co −1 atom and the Curie temperature was clarified to be higher than 400 K, in consistent with the bulk behavior.…”

Hinge-like Co2S3and Co2Te3Nanosheets: Promising Two-Dimensional Optical, Thermoelectric, and Spintronic Materials

“…In 2017, Huang et al demonstrated the existence of an intrinsic long-range magnetic order in two-dimensional materials by successfully synthesizing single-layer CrI 3 with a T C of 45 K, which was followed by extensive studies to find 2D nanosheets with more practical magnetic properties . MnSe 2 , CrTe 2 , VSe 2 , and CrSe 2 are some of the TMC magnetic nanosheets that have been successfully synthesized. − Also, the magnetic properties of Cr 2 Te 3 , Cr 2 S 3 , Co 2 S 2 , and Co 2 Se 3 nanosheets have been predicted using first-principles calculations. − According to the oxidation states of transition metals, they can exhibit various magnetic states in combination with other elements. For example, 2D CrO 2 and 2D Cr 2 O 3 nanosheets are a half-metallic ferromagnetic and a ferromagnetic semiconductor with Curie temperatures of 686 and 332 K, respectively, which can be used in spintronic devices due to their high T C and large magnetic anisotropy energy (MAE). − 2D structures of cobalt telluride are magnetic nanosheets with different stoichiometries.…”

“…MnSe 2 , CrTe 2 , VSe 2 , and CrSe 2 are some of the TMC magnetic nanosheets that have been successfully synthesized. − Also, the magnetic properties of Cr 2 Te 3 , Cr 2 S 3 , Co 2 S 2 , and Co 2 Se 3 nanosheets have been predicted using first-principles calculations. − According to the oxidation states of transition metals, they can exhibit various magnetic states in combination with other elements. For example, 2D CrO 2 and 2D Cr 2 O 3 nanosheets are a half-metallic ferromagnetic and a ferromagnetic semiconductor with Curie temperatures of 686 and 332 K, respectively, which can be used in spintronic devices due to their high T C and large magnetic anisotropy energy (MAE). − 2D structures of cobalt telluride are magnetic nanosheets with different stoichiometries. Negedu et al successfully synthesized 2D CoTe, CoTe 2 , and Co 2 Te 3 layers using the liquid-phase exfoliation method.…”