Estudio de la transición de fase metal-semiconductor en dióxido de vanadio

Abstract

In this thesis we made a study about the Metal-Insulator phase transition with the purpose to determine, particularly, the parameters to play a important rol in the transition. For this we made a study of theories or models that exist currently about materials with different grade of disorder, the importance of correlation between electrons and the dimensionality of the system. Finally we choose for the treatment of our data a model derived from the scaling theory. We implemented a curve fit to experimental data of Electric Conductance G Vs Temperature, in thin film of Vanadium Dioxide V O2, and we obtained a specific functional form for carrier density δn in function of temperature. Additionally we define a rough criteria of critical region in terms of a interval of conductances that include the critical conductance gc. We proposed functional forms for curve fit of the conductance g in function of T to regions out of critical region, they been valid for our experimental data. All this for describe a full hysteresis cycle.

Finally we make a brief discussion about the values of found parameters on every one of the region.