Amorphous and sheet dichalcogenides of Group IVb, Vb, molybdenum and tungsten
US4299892A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 28, 1980 |
| Grant date | Nov 10, 1981 |
| Priority date | — |
| Expiry date | Jul 28, 2000 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S505/824
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
Dichalcogenides of Group IVb, Vb, molybdenum and tungsten of two new forms have been discovered. The two new forms are the amorphous and layered-sheet configurations. In particular, the dichalcogenides of Group IVb, Ib, molybdenum and tungsten, i.e. Z(MX.sub.2).sub.n wherein M is the metal and X is the chalcogen, n is at least about 20,000 and Z is the number of such (MX.sub.2).sub.n sheets ranging from 1-10, can be described as possessing a "rag-like" structure representing a system consisting of single or several stacked but randomly folded and disordered layers or sheets having dimensions (as determined by TEM) corresponding to about 6.2 to 62 A in thickness, about 500 A minimum length by about 500 A minimum width. Broadly the rag-like (MX.sub.2).sub.n can be likened to a stack of polymer sheets wherein each sheet is one atom thick. These sheets of (MX.sub.2).sub.n are prepared by the controlled heating (in a flowing stream of H.sub.2 /H.sub.2 S) of amorphous MX.sub.2 obtained by the monaqueous low temperature precipitation of MX.sub.2 from mixtures of the metal salt and sources of sulfur, selenium or tellurium.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.