Temperature Calibration and Electrode Preparation for Use in the Study of Ionic Conductivity of AgBr Thin Films

AgBr thin films contain many dislocations and these are the source of silver interstitials, The sub-surface space-charge layer, rich in silver interstitials, is responsible for ionic conductance of the AgBr thin film. Thin films of gold (Au) are prepared on cleaved mica substrates in order to make the electrical connections for measuring the ionic conductivity across the AgBr thin film. The gold and silver bromide (AgBr) evaporations are done using oil-diffusion and ion-pumping vacuum systems, respectively. Ionic conductivity measurements are done as a function of temperature for each of the thin films. A series of temperature calibration experiments for the sample holder were done to enable the determination of the temperature of the sample during ionic conductivity measurements. The calibration experiments were performed in different bell-jar environmental conditions-vacuum (10E-9 Torr) and several other intermediate pressure ranges, using ultra high purity nitrogen gas as a thermal exchange gas