Ac Field Effects in Evaporation of Sodium Chloride, Cadmium Sulfide, and Silver onto Fused Silica

Abstract

Ac field effects (i.e., preferred orientation and enhanced crystallite size) have been noted on the structure of evaporated NaCl, CdS, and Ag films on fused silica substrates over a temperature range of −100 ° to +200 °C, a frequency range of 20 Hz–2 MHz and a voltage gradient range of 15–500 V/cm. For each material the effect of frequency at room temperature is greatest at about 104 Hz, but this maximum is rather shallow. The ac field effect on NaCl is greater at −100 °C than at room temperature or 200 °C. Sodium chloride films show greater effects of preferred orientation and crystallite size enhancement at 25 °C than do CdS or Ag.