Metastable 1T'-phase group VIB transition metal dichalcogenide crystals
Zhuangchai Lai1,2, Qiyuan He3, Thu Ha Tran2
1Department of Chemistry, City University of Hong Kong, Hong Kong SAR, China.
Nature Materials
|April 16, 2021
Summary
Researchers developed a new method to synthesize metastable 1T'-phase transition metal dichalcogenides (1T'-TMDs). This breakthrough enables large-scale production of these unique semi-metallic materials, facilitating further scientific exploration.
Area of Science:
- Materials Science
- Condensed Matter Physics
- Solid State Chemistry
Background:
- Metastable 1T"-phase transition metal dichalcogenides (1T"-TMDs) are of significant interest due to their unique structures and properties.
- The synthesis of high-quality 1T"-TMD crystals, particularly group VIB TMDs, presents a considerable challenge.
Purpose of the Study:
- To develop a general synthetic method for the large-scale preparation of metastable 1T"-phase group VIB TMDs.
- To investigate the structural and physical properties of these synthesized materials.
Main Methods:
- A novel general synthetic method was employed for the preparation of 1T"-TMDs.
- Single-crystal X-ray diffraction was used to determine the crystal structures of 1T"-WS2, -WSe2, -MoS2, and -MoSe2.
- Thickness-dependent superconductivity was measured for 1T"-WS2.
Main Results:
- Successful large-scale synthesis of metastable 1T"-phase group VIB TMDs, including WS2, WSe2, MoS2, MoSe2, and their alloys.
- Crystal structures of 1T"-WS2, -WSe2, -MoS2, and -MoSe2 were solved.
- 1T"-WS2 demonstrated thickness-dependent intrinsic superconductivity with critical temperatures of 8.6 K (90.1 nm) and 5.7 K (single layer).
Conclusions:
- The developed synthesis method provides a pathway for the scalable production of metastable 1T"-TMDs.
- The observed superconductivity in 1T"-WS2 is attributed to its high carrier concentration and semi-metallic nature.
- This work facilitates systematic investigations into the intrinsic properties of metastable TMDs.
Related Concept Videos
02:46Crystal Field Theory - Tetrahedral and Square Planar Complexes
45.8K
Tetrahedral Complexes
Crystal field theory (CFT) is applicable to molecules in geometries other than octahedral. In octahedral complexes, the lobes of the dx2−y2 and dz2 orbitals point directly at the ligands. For tetrahedral complexes, the d orbitals remain in place, but with only four ligands located between the axes. None of the orbitals points directly at the tetrahedral ligands. However, the dx2−y2 and dz2 orbitals (along the Cartesian axes) overlap with the ligands less than the dxy,...
Crystal field theory (CFT) is applicable to molecules in geometries other than octahedral. In octahedral complexes, the lobes of the dx2−y2 and dz2 orbitals point directly at the ligands. For tetrahedral complexes, the d orbitals remain in place, but with only four ligands located between the axes. None of the orbitals points directly at the tetrahedral ligands. However, the dx2−y2 and dz2 orbitals (along the Cartesian axes) overlap with the ligands less than the dxy,...
45.8K
02:58Crystal Field Theory - Octahedral Complexes
28.7K
Crystal Field Theory
To explain the observed behavior of transition metal complexes (such as colors), a model involving electrostatic interactions between the electrons from the ligands and the electrons in the unhybridized d orbitals of the central metal atom has been developed. This electrostatic model is crystal field theory (CFT). It helps to understand, interpret, and predict the colors, magnetic behavior, and some structures of coordination compounds of transition metals.
CFT focuses on...
To explain the observed behavior of transition metal complexes (such as colors), a model involving electrostatic interactions between the electrons from the ligands and the electrons in the unhybridized d orbitals of the central metal atom has been developed. This electrostatic model is crystal field theory (CFT). It helps to understand, interpret, and predict the colors, magnetic behavior, and some structures of coordination compounds of transition metals.
CFT focuses on...
28.7K
02:42Valence Bond Theory
10.0K
Coordination compounds and complexes exhibit different colors, geometries, and magnetic behavior, depending on the metal atom/ion and ligands from which they are composed. In an attempt to explain the bonding and structure of coordination complexes, Linus Pauling proposed the valence bond theory, or VBT, using the concepts of hybridization and the overlapping of the atomic orbitals. According to VBT, the central metal atom or ion (Lewis acid) hybridizes to provide empty orbitals of suitable...
10.0K
02:37Metallic Solids
19.8K
Metallic solids such as crystals of copper, aluminum, and iron are formed by metal atoms. The structure of metallic crystals is often described as a uniform distribution of atomic nuclei within a “sea” of delocalized electrons. The atoms within such a metallic solid are held together by a unique force known as metallic bonding that gives rise to many useful and varied bulk properties.
All metallic solids exhibit high thermal and electrical conductivity, metallic luster, and malleability....
All metallic solids exhibit high thermal and electrical conductivity, metallic luster, and malleability....
19.8K
02:33Phase Transitions: Sublimation and Deposition
18.8K
Some solids can transition directly into the gaseous state, bypassing the liquid state, via a process known as sublimation. At room temperature and standard pressure, a piece of dry ice (solid CO2) sublimes, appearing to gradually disappear without ever forming any liquid. Snow and ice sublimate at temperatures below the melting point of water, a slow process that may be accelerated by winds and the reduced atmospheric pressures at high altitudes. When solid iodine is warmed, the solid sublimes...
18.8K
02:58Properties of Transition Metals
28.1K
Transition metals are defined as those elements that have partially filled d orbitals. As shown in Figure 1, the d-block elements in groups 3–12 are transition elements. The f-block elements, also called inner transition metals (the lanthanides and actinides), also meet this criterion because the d orbital is partially occupied before the f orbitals.
28.1K