Water adlayers on aluminum oxide thin films

The effect of saturated water vapor on the performance of quartz cavities covered by magnetronsputtered oxide films is considered. A technique for precisely estimating the influence of small vapor concentrations on the frequency of the quartz cavities is described. Adsorption on the Al$_2$O$_3$ surface is characterized with a new model that allows one to list water layers on the surface and correlate the number of adlayers with experimental conditions. The estimated adsorption parameters agree well with available experimental data and results obtained by other authors.