Phase-transfer induced room temperature ferromagnetic behavior in 1T@2H-MoSe2 nanosheets

Xia, Baorui; Wang, Tongtong; Xiao, Wen; Zhang, Rongfang; Liu, Peitao; Ding, Jun; Gao, Daqiang; Xue, Desheng

doi:10.1038/srep45307

Cited by 27 publications

(30 citation statements)

References 39 publications

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“…Notably, for the Cr-2.1, Cr-2.5, and Cr-4.3 samples, we can see randomly distributed brighter spots marked by yellow circles along the [010] direction (Figure S7a,c,e, Supporting Information), which were considered to be Cr atoms as the corresponding intensity spectra (Figure S7b,d,f, Supporting Information). Therefore, the atomic images here confirmed that the Cr atoms were randomly incorporated into the MoTe 2 lattice by substituting the Mo sites, and no Cr-related clusters were formed. − …”

Section: Results and Discussionmentioning

confidence: 52%

Tunable and Robust Near-Room-Temperature Intrinsic Ferromagnetism of a van der Waals Layered Cr-Doped 2H-MoTe₂ Semiconductor with an Out-of-Plane Anisotropy

Yang

Zhang

et al. 2021

ACS Appl. Mater. Interfaces

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The intrinsically nonmagnetic feature of van der Waals (vdW) layered transition-metal dichalcogenide (TMDC) semiconductors limits the spintronic applications of these semiconductors. In this paper, we demonstrate a facile Te flux strategy to induce intrinsic ferromagnetism in the vdW layered 2H-MoTe2 semiconductor by magnetic chromium (Cr) doping. The Curie temperature (T c) and saturation magnetization (M s) can be well tuned by adjusting the Cr doping concentration. A notable T c up to 275 K can be achieved for the vdW layered Cr-doped 2H-MoTe2 bulk crystals, which is much higher than that of recently reported van der Waals ferromagnetic semiconductors (T c is mostly less than 70 K), in contrast to the diamagnetic feature of the pristine MoTe2. Meanwhile, the highest M s of the vdW layered Cr-doped 2H-MoTe2 bulk crystals can reach 4.78 emu g–1, which is stronger than most values reported for magnetic-element-doped van der Waals materials. In addition, all of the as-grown semiconducting Cr-doped 2H-MoTe2 (Cr-2H-MoTe2) single crystals display a large magnetic anisotropy with an out-of-plane easy axis of magnetization. The observed ferromagnetism in the Cr-2H-MoTe2 has intrinsic characteristics, which can be mainly attributed to the spin polarization caused by Cr doping as confirmed by the density functional theory (DFT) calculations. Our approach offers an avenue to tune the ferromagnetism in the vdW layered semiconductor and explore its diverse spintronic and magnetoelectric applications.

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Section: Results and Discussionmentioning

confidence: 52%

Tunable and Robust Near-Room-Temperature Intrinsic Ferromagnetism of a van der Waals Layered Cr-Doped 2H-MoTe₂ Semiconductor with an Out-of-Plane Anisotropy

Yang

Zhang

et al. 2021

ACS Appl. Mater. Interfaces

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“…Typically, the A 1g band is exclusively assigned to 2H-MoSe 2 , while the E 2g 1 and J 2 peaks are the characteristic features of 1T-MoSe 2 . It can be seen that, in comparison with that of a-MoSe 2 , the intensities of E 2g 1 and J 2 peaks for e-MoSe 2 are much stronger than the A 1g band, indicating that there exist more 1T phases . It has been reported that the inserted NH 4 + can donate electrons to the MS 2 (M = Mo/W) hosts, changing the d-band filling state of Mo, thus inducing the phase transition from trigonal prismatic (2H) to octahedron (1T). − Therefore, similar to our study, it is believed that the intercalated NH 4 + decomposed from NH 2 C 2 H 4 NH 2 facilitates the stabilization of 1T-MoSe 2 during hydrothermal reaction.…”

Section: Results and Discussionmentioning

confidence: 97%

Ammonium Intercalation Induced Expanded 1T-Rich Molybdenum Diselenides for Improved Lithium Ion Storage

Zhou

Wang

Chang

et al. 2021

ACS Appl. Mater. Interfaces

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Transition metal dichalcogenides (TMDs), particularly molybdenum diselenides (MoSe2), have the merits of their unique two-dimensional (2D) layered structures, large interlayer spacing (∼0.64 nm), good electrical conductivities, and high theoretical capacities when applied in lithium-ion batteries (LIBs) as anode materials. However, MoSe2 remains suffering from inferior stability as well as unsatisfactory rate capability because of the unavoidable volume expansion and sluggish charge transport during lithiation-delithiation cycles. Herein, we develop a simultaneous reduction-intercalation strategy to synthesize expanded MoSe2 (e-MoSe2) with an interlayer spacing of 0.98 nm and a rich 1T phase (53.7%) by rationally selecting the safe precursors of ethylenediamine (NH2C2H4NH2), selenium dioxide (SeO2), and sodium molybdate (Na2MoO4). It is noteworthy that NH2C2H4NH2 can effectively reduce SeO2 and MoO4 2– forming MoSe2 nanosheets; in the meantime, the generated ammonium (NH4 +) efficiently intercalates between MoSe2 layers, leading to charge transfer, thus stabilizing 1T phases. The obtained e-MoSe2 exhibits high capacities of 778.99 and 611.40 mAh g–1 at 0.2 and 1 C, respectively, together with excellent cycling stability (retaining >90% initial capacity at 0.2 C over 100 charge–discharge cycles). It is believed that the material design strategy proposed in this paper provides a favorable reference for the synthesis of other transition metal selenides with improved electrochemical performance for battery applications.

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“…1c, the peak (marked as A1g) is the exclusive peak of MoSe2 2H structure, whilst the peaks (donated as E2g 1 , J2) are the characteristic peaks for 1T peaks. [17] Thus, it is concluded that PMS and CMS are composed of 1T/2H phases, and the existed 1T phase would increase metallic properties of MoSe2, which is beneficial for electrochemical properties. [18] Moreover, it is expected for PMS, that its peak at 240 cm -1 was shifted to the lower wavenumbers, and that its peak at 280 cm -1 moves towards the higher wavenumbers, demonstrating the few-layered MoSe2 were effectively formed.…”

Section: Resultsmentioning

confidence: 98%

Binding MoSe2 with carbon constrained in carbonous nanosphere towards high-capacity and ultrafast Li/Na-ion storage

Hou

Banks

et al. 2018

Energy Storage Materials

207

114

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Mostly reported MoSe2 suffered from easily stacking problem, volume expansion and relative low capacity. From the experience of Li/Na-Se batteries, the exfoliated and encapsulated MoSe2 inside carbon nanospheres with C-O-Mo bonds and large layer distance (0.89 nm) are successfully constructed. This unique effective structure has C-O-Mo bonding allowing high conductivity across the Se-O insulation layer and promoting its reversible conversion. The first-principles calculations demonstrated that the frontier molecular orbitals of C-O-Mo interface structure are mainly localized on the MoSe2 sheet fragment with an appropriate HOMO-LUMO gap (< 4eV),suggesting its good stability and conductivity. Utilized as anodes for LIBs allows a Li-storage capacity to be realized of 1208 mAh g -1 after 150 cycles at 1.0 A g -1 and 519 mAh g -1 after 200 cycles at 4.0 A g -1 . The Na-storage capacity is found to be 543, 491 mAh g -1 after 120 cycles at 0.1, 1.0 A g -1 . Focusing on the analysis of CV, the reducing particle may improve the capacitive behaviors, further resulting the high-rate performance. Ex-situ techniques demonstrated that the emerging Se was constrained uniformly. The controlling of by-product Se plays a key role in achieving a high rate 2 capacity and cycling stability, and opens up a potential avenue for these metal-selenide anodes designs for battery storage systems.

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Phase-transfer induced room temperature ferromagnetic behavior in 1T@2H-MoSe2 nanosheets

Cited by 27 publications

References 39 publications

Tunable and Robust Near-Room-Temperature Intrinsic Ferromagnetism of a van der Waals Layered Cr-Doped 2H-MoTe₂ Semiconductor with an Out-of-Plane Anisotropy

Tunable and Robust Near-Room-Temperature Intrinsic Ferromagnetism of a van der Waals Layered Cr-Doped 2H-MoTe₂ Semiconductor with an Out-of-Plane Anisotropy

Ammonium Intercalation Induced Expanded 1T-Rich Molybdenum Diselenides for Improved Lithium Ion Storage

Binding MoSe2 with carbon constrained in carbonous nanosphere towards high-capacity and ultrafast Li/Na-ion storage

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Phase-transfer induced room temperature ferromagnetic behavior in 1T@2H-MoSe2 nanosheets

Cited by 27 publications

References 39 publications

Tunable and Robust Near-Room-Temperature Intrinsic Ferromagnetism of a van der Waals Layered Cr-Doped 2H-MoTe2 Semiconductor with an Out-of-Plane Anisotropy

Tunable and Robust Near-Room-Temperature Intrinsic Ferromagnetism of a van der Waals Layered Cr-Doped 2H-MoTe2 Semiconductor with an Out-of-Plane Anisotropy

Ammonium Intercalation Induced Expanded 1T-Rich Molybdenum Diselenides for Improved Lithium Ion Storage

Binding MoSe2 with carbon constrained in carbonous nanosphere towards high-capacity and ultrafast Li/Na-ion storage

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Tunable and Robust Near-Room-Temperature Intrinsic Ferromagnetism of a van der Waals Layered Cr-Doped 2H-MoTe₂ Semiconductor with an Out-of-Plane Anisotropy

Tunable and Robust Near-Room-Temperature Intrinsic Ferromagnetism of a van der Waals Layered Cr-Doped 2H-MoTe₂ Semiconductor with an Out-of-Plane Anisotropy