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
| Limitations: |
 APPROVED FOR PUBLIC RELEASE |
| Description: |
Interim rept. |
| Pages: |
16 |
| Report Date: |
01 AUG 50 |
| Report Number: |
A773592 |
|
|
|
|
Keywords relating to this report:
