Data are presented on the dissolution rates of SiO2 films in a variety of acidic fluoride solutions. It is shown that the rate of dissolution is linearly dependent on the concentration of HF2− and HF in relatively dilute fluoride solutions. Both reactions have a similar temperature dependence characterized by an activation energy of 9.1 and 8.1 kcal/mole, respectively. The reaction with HF2− is about four to five times as fast as that with HF. Extrapolation to more concentrated solutions suggests that higher polymeric species of the type HxFx+1− may also be active in the dissolution process. Raman data indicates that no single product species is formed although the product spectrum is consistent with the presence of some SiF62− .

No abstract

Thin magnetic films of Co‐P were prepared in two somewhat different electroless cobalt solutions. The magnetic properties and the corrosion behavior of these films as a function of thickness was studied. The films exhibited high coercivities with a maximum of about 1000 oe at a thickness of 600Aå. The magnetic moment of these films was found to decrease on exposure to high humidity and moderate temperatures (40°–70°C); this was used as a means of studying the extent of corrosion. The extent of corrosion was found to vary as the 2/3 power of the thickness of the film.

No abstract