CONDUCTION IN RUO2-BASED THICK-FILMS

The dependence of RuO2-glass thick-film electrical conductivity on the concentration of metallic component reveals a metal-insulator transit ion. Resistance versus temperature characteristics measured in the ran ge 4.2-400 K are presented for a set of seven composites of varying co mposition. The results obtained can be divided into two groups: compos ites incorporating greater than or equal to 0.12 (per unit volume) of metallic component yield minima of R(T) curves and possess parabola-li ke shapes, and composites with a small content of metallic component ( <0.12) show a negative temperature coefficient of resistance over the whole range of measured temperatures. In the insulating region, data a re analysed in terms of various conduction mechanisms, giving rise to an understanding of electrical conduction in RuO2-glass thick resistiv e films.