Thin film controllers

Figure 2.1. Processing stages in chemical solution deposition of thin films. Controllable parameters are shown on the left dependent processes are shown in italics. [Reprinted from Ref. 16 with the permission of the publisher, Taylor Francis, Ltd. R. W. Schwartz et al., Sol-gel processing of PZT thin films a review of the state-of-the-art and process optimization strategies, Int. Ferro., 7,259, (1995).]...

The analogous voltammograms for a thin-film control electrode containing an essentially identical quantity of TiS2 are shown as the dotted curves... 

The decreased contribution of film resistance for the microtubular electrode makes sense because the effective film thickness for the microtubular system is less than for the thin film control electrode. This is because the surface area of the microtubular current collector is eight times higher than the surface area of the planar current collector. (This factor is calculated from the membrane thickness and the density and diameter of the pores in the membrane.) Since the control and microtubular electrodes contain the same amount of TiS2, the eight times higher underlying surface area of the microtubular electrode means that the TiS2 film is effectively a factor of 8 thinner, relative to the control electrode. 

Thin film controllers and control units with quartz oscillators... 

The quartz oscillator coating thickness gauge (thin film controller) utilizes the piezoelectric sensitivity of a quartz oscillator (monitor crystal) to the supplied mass. This property is utilized to monitor the coating rate and final thickness during vacuum coating. 

Figure 3.6 Capacity vs. cycle number for the nanostructured Sn02 and thin-film control electrodes at a charge-discharge rate of 8°C over the potential window of 0.2-0.9 V. Reprinted with permission from Ref. 19.

A number of studies were done in order to determine which of these various factors contribute to the large peak separations observed here. First, it is well known that the effects of resistive elements can be obviated by applying positive feedback [132]. When positive feedback was applied to a thin-film control electrode similar to that described in Fig. 27, the peak separation decreased from —0.8 to —0.35 V (Fig. 28). These data show that resistance does, indeed, contribute to the large AEp values observed here. However, the fact that —0.35 V of this peak splitting cannot be removed by applying positive feedback clearly indicates that slow electron transfer kinetics also contribute to AEj. ... 

We have generalized this analysis to statistically seifsimilar structures. We will assume that the spreading coefficient S = yc - (y + y) is negative. For this case, the liquid A wets only partially a smooth surface made of the grain material. Then the cocoon cannot be formed on a smooth surface (Dy 2). On the other hand, in the case of complete wetting (S > 0), an ultra thin film controlled by long-range van der Waals forces will be formed. 

---