Accession Number : ADA295377

Title :   The Properties of Evaporated Gold and Tungsten Oxides.

Descriptive Note : Interim rept.,

Corporate Author : NAVAL RESEARCH LAB WASHINGTON DC

Personal Author(s) : Wilkinson, P. G.

PDF Url : ADA295377

Report Date : 01 AUG 1950

Pagination or Media Count : 16

Abstract : Gold blacks prepared by evaporating gold from a tungsten filament in tank nitrogen at several millimeters pressure were found to contain tungsten oxides which greatly affected the optical and electrical properties. Deposits containing more than 0. 5 mol% of tungsten oxides were black and showed resistivities 10(exp 3) to 10(exp 8) times that of bulk gold. The resistivities of gold black increased on exposure to oxygen. On the other hand, oxide-free deposits were yellow and possessed a 10% stable resistivity, unaffected by exposure to oxygen. Exposure to air or oxygen caused an increase in the electrical resistance and optical transmission of films of tungsten dioxide and tungsten trioxide evaporated in high vacuum. It was concluded that evaporated films of pure gold are unaffected by exposure to air, and that the changes in optical and electrical characteristics often observed in evaporated gold films exposed to air may be attributed to contamination by oxides of tungsten. jg p.4

Descriptors :   *EVAPORATION, *GOLD, *TUNGSTEN OXIDES, OPTICAL PROPERTIES, RADIATION, EXPOSURE(GENERAL), AIR, ELECTRICAL PROPERTIES, NITROGEN, OXYGEN, COATINGS, PURITY, OXIDES, ABSORBERS(MATERIALS), LIGHT TRANSMISSION, FILAMENTS, ELECTRICAL RESISTANCE, CONTAMINATION, THERMOCOUPLES, TUNGSTEN, BLACK(COLOR), BOLOMETERS, HIGH VACUUM, DIOXIDES.

Subject Categories : Inorganic Chemistry
      Physical Chemistry
      Radiation and Nuclear Chemistry
      Electricity and Magnetism
      Optics

Distribution Statement : APPROVED FOR PUBLIC RELEASE