World Journal of Condensed Matter Physics,2014, 4, 166-178 Published Online August 2014 in SciRes. http://www.scirp.org/journal/wjcmp http://dx.doi.org/10.4236/wjcmp.2014.43021 How to cite this paper: Abdurakhmanov, G. (2014) On the Conduction Mechanism of Silicate Glass Doped by Oxide Com- pounds of Ruthenium (Thick Film Resistors). 3. The Minimum of Temperature Dependence of Resistivity. World Journal of Condensed Matter Physics, 4, 166-178. http://dx.doi.org/10.4236/wjcmp.2014.43021 On the Conduction Mechanism of Silicate Glass Doped by Oxide Compounds of Ruthenium (Thick Film Resistors). 3. The Minimum of Temperature Dependence of Resistivity Gulmurza Abdurakhmanov The Institute of Power Engineering and Automation, The Uzbek Academy of Sciences, Tashkent, Uzbekistan Email: gulmirzo@mail.ru Received 2 June 2014; revised 5 July 2014; accepted 21 July 2014 Copyright © 2014 by author and Scientific Research Publishing Inc. This work is licensed under the Creative Commons Attribution International License (CC BY). http://creativecommons.org/licenses/by/4.0/ Abstract This article is the final part of the investigation of conduction mechanism of silicate glass doped by oxide compounds of ruthenium (thick film resistors). In the first part [1], the formation of percola- tion levels due to diffusion of dopant atoms into the glass has been considered. The diffusion me- chanism allowed us to explain shifting of the percolation threshold towards to lower value and the effect of firing conditions as well as the components composition on the electrical conduction of the doped glass. The coexistence of thermal activation and localization of free charge carriers as the result of nanocrystalline structure of the glass was the subject of the second part [2]. Because of it, the resistivity of the doped silicate glass is proportional to exp (–aT –ζ ) at low temperatures (T < 50 K), 0.4 < ζ < 0.8. Structural transitions of nanocrystals take place at high temperatures (T > 800 K) and the conductivity of the doped silicate glass decreases sharply. We consider the origin of the minimum in the temperature dependence of resistivity of the doped silicate glass here. It is shown that the minimum arises from merge of impurity band into the valence band of glass at tempera- ture high enough, so thermal activation of charge carriers as well as its hopping are failed, and scattering of free charge carriers become predominant factor in the temperature dependence of the resistivity. Keywords Lead-Silicate Glass, Thick Film Resistors, Minimum of Resistivity, Doping, Energy Bands, Conductivity, Thermal Activation, Hopping