Superconducting transition in polycrystalline YBa2Cu3O7-x: diving into the meaning of Tc and the excess of electrical conductivity in the normal state

Treballs Finals de Grau de Física, Facultat de Física, Universitat de Barcelona, Curs: 2023, Tutor: Antoni García-SantiagoSuperconductivity is the property of certain materials to conduct direct current electricity without energy loss when they are cooled below a critical temperature . The transition at this temperature is driven by thermal fluctuations, so deciding the exact value of is not a trivial matter. In this work we show different methods that have been used to estimate this temperature and deepen our understanding of the excess conductivity due to fluctuations. We can detect the mean-field, fluctuations, and full critical regions as they change with temperatur