High-Temperature Superconductivity in Bridge and Layer Compounds

Abstract

compounds, where A is a monovalent atom or radical, T is an even-valence transition metal, C is a chalcogenide, and the parameters x and y lie in the ranges 0.1<#<,0.3, O^y < 0.5. The model explains why the maximum superconducting transition temperature T s m&x is higher than 12°K in bridge compounds withy =0.1, although the maximum value of T s observed in related layer compounds with y =0.0 is about 6°K.

Electron states and bonding in titanium sulfide

“…The first five conduction bands are predomi- Reference [7]. The next (s-like) conduction band lies several volts higher, contrary to some earlier models proposed [ 6 ] , and has mixed metal-ligand character. These results are quite comparable with the TiSs MO levels discussed previously, the noticeable differences being…”

Semimetal or Semiconductor: The Nature of High Intrinsic Electrical Conductivity in TiS2

“…However, anion vacancies are known to be abundant in transition metal dichalcogenide materials, which may serve as the donor defects too. Other defects such as a Ti Frenkel pair (Ti F ), sometimes called a displacement Ti defect, have also been considered as the cause for the self-doping. − TiS 2 has been experimentally shown to exhibit a complex relation between conductivity and temperature, , which is directly related to the defect physics of this material. So far, there has been no direct identification of the dominant defects in TiS 2 other than the nonstoichiometry arguments.…”