Transfer of molybdenum disulfide to various metals

Sliding friction experiments were conducted with molybdenum disulfide single crystals in contact with sputter cleaned surfaces of copper, nickel, gold, and 304 stainless steel. Transfer of the molybdenum disulfide to the metals was monitored with Auger electron spectroscopy. Results of the investigation indicate molybdenum disulfide transfers to all clean metal surfaces after a single pass over the metal surface with film thickness observed to increase with repeated passes over the same surfaces. Large particle transfer occurs when the orientation of the crystallites is other than basal. This is frequently accompanied by abrasion of the metal. Adhesion of molybdenum disulfide films occurred readily to copper and nickel, less readily to 304 stainless steel, and even less effectively to the gold, which indicates a chemical effect

Near-Infrared Plasmon-Induced Hot Electron Extraction Evidence in an Indium Tin Oxide Nanoparticle/Monolayer Molybdenum Disulfide Heterostructure

: In this work, we observe plasmon-induced hot electron extraction in a heterojunction between indium tin oxide nanocrystals and monolayer molybdenum disulfide. We study the sample with ultrafast differential transmission, exciting the sample at 1750 nm where the intense localized plasmon surface resonance of the indium tin oxide nanocrystals is and where the monolayer molybdenum disulfide does not absorb light. With the excitation at 1750 nm, we observe the excitonic features of molybdenum disulfide in the visible range, close to the exciton of molybdenum disulfide. Such a phenomenon can be ascribed to a charge transfer between indium tin oxide nanocrystals and monolayer molybdenum disulfide upon plasmon excitation. These results are a first step toward the implementation of near-infrared plasmonic materials for photoconversion

An analysis of the variation in wear life of hot pressed molybdenum disulfide-silver electrical contact brushes in vacuum

Wear life analysis of hot pressed molybdenum disulfide-silver electrical contact brushes in vacuu

Molybdenum disulfide mixtures make effective high-vacuum lubricants

Five different mixtures of molybdenum disulfide are found to be effective bearing lubricants when tested at very low pressures and high temperatures

Growth and Characterization of Molybdenum Disulfide Thin Films

Two-dimensional materials, or materials that are only one atomic layer thick, have seen much research in recent years because of their interesting electrical properties. The first of these materials, graphene, was found to have incredible electrical properties but lacked a bandgap in intrinsic films. Without a bandgap, graphene cannot create transistors that can be shut off. Molybdenum disulfide, however, is a two-dimensional semiconductor with a large bandgap. The main issue of molybdenum disulfide is that synthesized films are a much lower quality than their exfoliated counterparts. For molybdenum disulfide to be able to be used practically, a method of synthesis must be found that can reliably create quality large area monolayer films. In this thesis, three methods of molybdenum disulfide film synthesis are presented. Methods implemented used a tube furnace as a chemical vapor deposition system to evaporate source materials to synthesize thin films of molybdenum disulfide. An exploration into the different synthesis parameters shows optimal conditions for these specific methods. Then a discussion of these different methods is presented by judging films grown by using these methods on relevant criteria. This work shows methods to synthesize large area, polycrystalline, small grain, multilayer films, both intrinsic and doped, and to synthesize small area, single crystal and polycrystalline, monolayer films of molybdenum disulfide

Spectroscopic study of double sulphides of molybdenum (IV) and rhenium (IV)

Dichalcogenides of transition metals are especially interesting. Majority of chalcoginides are semiconductors and some of them show interesting properties in certain regions of optical spectrum. Such properties allow application of these compounds in optico-electronics, radio-photonics, laser physics etc. Direct synthesis one of simple chalcogenides - rhenium disulphide - has been carried out from source components: metallic rhenium and elemental sulfur. In this research we used high temperature annealing at 1000 0C and the pressure of 10-5 atm in 24 hours. The synthesis was carried out in a sealed quartz ampoule. Photoelectron spectra and IR absorption spectra of molybdenum disulfide (IV) and rhenium disulfide (IV) were measured during the research. We shows that rhenium disulfide (IV) crystallize in CdI2 structural type. S2p sulfur bond energy for molybdenum disulfide (IV) and rhenium disulfide (IV) are at almost identical values. IR spectrum analysis shows that rhenium disulfide (IV) structure compared with molybdenum disulfide (IV)

Onset of superconductivity in sodium and potassium intercalated molybdenum disulphide

Molybdenum disulfide in the form of natural crystals or powder has been intercalated at -65 to -70 C with sodium and potassium using the liquid ammonia technique. All intercalated samples were found to show a superconducting transition. A plot of the percent of diamagnetic throw versus temperature indicates the possible existence of two phases in the potassium intercalated molybdenum disulfide. The onset of superconductivity in potassium and sodium intercalated molybdenite powder was found to be approximately 6.2 and approximately 4.5 K, respectively. The observed superconductivity is believed to be due to an increase in electron density as a result of intercalation