Received November 10, 2005, revised February 13, 2006
We have investigated the evolution of the temperature dependence of the in-plane and off-plane conductivity of YBa2Cu3O7–d single crystals due to the decrease of the oxygen content in the samples caused by a heat treatment. The concentration dependence of the in-plane and off-plane energy gaps has been determined. It has been shown that the enhancement of the localization effects results in a suppression of the pseudogap state. At the same time, the decrease of the
oxygen content results in a relative narrowing of the temperature interval in which the regime of the fluctuating conductivity is realized.PACS: 74.72.Bk - Y-based cuprates
Key words: YBa2Cu3O7–d single crystals, preudogap, localization, oxygen content, crossover.