Influence of surface catalytic reactions on crystal unit ageing

The authors investigate mechanisms of crystal unit frequency variations depending on metallized piezoelectric elements, namely, the interaction of electrode material with the environment. It is shown that the existence of Na- and Ca-type contaminants accelerates and those of S and Cr slow the reaction rate. There is a direct relation between the positive component of quartz crystal unit aging and the value of catalytic activity of the electrode. Silver emission from the electrode surface accompanying catalytic silver oxidation both during the manufacture and the storage of quartz crystal units was detected