Structural, optical, magnetic and electrochemical properties of hydrothermally synthesized WS2 nanoflakes

The temperature-independent paramagnetism susceptibility peak at zero magnetic fields in the non-topological WSe2 single crystal

“…There are several studies reporting that the zigzag edge structure, lattice distortion, structure vacancies might lead to the intrinsic ferromagnetism in topological materials and two-dimensional transition-metal dichalcogenides at room temperature. [10][11][12][13][14][15][16][17][18][19][20] Our results support that the temperatureindependent paramagnetism susceptibility peak might originate from the ferromagnetism induced by the lattice dislocation. Recently, experimental and theoretical studies demonstrated that an transition occurred in an atomically an antiferromagnetism-to-ferromagnetism crossover transition in an atomically thin semiconducting PtSe 2 twodimensional transition-metal dichalcogenide.…”

Hydrothermally Grown VS2 Nanosheets: A Material for Optical Limiting Applications

“…32 The A and B excitonic transitions in TMDC materials arise from the energy splitting of the valence band due to spin−orbit coupling. 20,33 The direct transitions from the split valence bands at the K point of the Brillouin zone give rise to A and B excitonic peaks. 34 The optical band gap energy of VS 2 nanostructures was estimated using the near band edge absorption relation…”

“…An exciton is a bound state of electron–hole pair that behaves similarly to hydrogen atoms . The A and B excitonic transitions in TMDC materials arise from the energy splitting of the valence band due to spin–orbit coupling. , The direct transitions from the split valence bands at the K point of the Brillouin zone give rise to A and B excitonic peaks . The optical band gap energy of VS 2 nanostructures was estimated using the near band edge absorption relation false( α h ν false) n = A ( h ν − E normalg ) where α is the optical absorption coefficient, h is Planck’s constant, ν is the frequency of incident radiation, n indicates the type of the transition, n = 2 or 0.5 for allowed direct or indirect transitions, respectively, A represents the constant independent of wavelength, and E g is the optical band gap energy.…”

One-step hydrothermal synthesis of WS2 as efficient electrode material for energy storage application

“…Figure 4 shows the RAMAN spectrum of WS2 nanosheets. Two peaks located at 348.15 cm -1 and 414.18 cm -1 are attributed to the in-plane (E 1 2g) and out-of-plane (A1g) modes signifies the 2H phase of WS2 [10,11]. In addition, three peaks at the low wavelength number appeared at 128.82 cm -1 , 172.87 cm -1 , and 261.6 cm -1 attribute to the 1T phase formation of WS2 [12].…”