In Reply to: Re: SiO evaporation posted by Barry Pemberton on 01/31/03 at 4:03 PM:
Silicon monoxide Patinal®. Evaporation temperature is 1200–1600ºC:
SiO2-layers. Evaporating Silicon monoxide in ionized oxygen yields layers which are transparent in the ultra violet down to 190 nm (190-8000 nm). The chemical composition of these layers is SiO2, the refractive index is identical to that of fused silica.
Si2O3-layers are produced by evaporation in oxygen atmosphere at pressures of 1-3x10-4mbar and with low evaporation rates, e.g. 20 nm/min. These layers are transparent in the visible and near infrared (380-8000 nm).
Optics areas of application:
antireflection coatings, e.g. for plastic spectacle lenses,
cold light mirrors, heat mirrors,
protective coatings, e.g. on Aluminium coatings of car head reflectors.
Silicon Dioxide Patinal®.
Evaporator - Electron beam evaporator with water-cooled copper crucible.
Evaporation temperature - 1800-2200ºC.
Deposition rate - about 1 nm/sec.
A relatively low electron beam voltage should be selected for evaporation of SiO2 (6-8 kV). SiO2 can be evaporated reactively as well as non-reactively. Typically an oxygen pressure of 1x10-4 mbar is used for reactive evaporation. SiO2 can be deposited on heated and unheated substrates and therefore is especially suited for the manufacture of hard and durable coatings on plastics. SiO2-Layers show amorphous structure. Range of transparency is 190-8000 nm (absorption band at 3000 nm).
Areas of application:
protective layers – multilayer coatings in combination with Titanium oxide, Hafnium oxide, Tantalum pentoxide,