Effect of electron irradiation on the pseudogap temperature dependence of YBa2Cu3O7-[delta] single crystals

(ProQuest: ... denotes formulae and/or non-USASCII text omitted; see image)The effect of electron irradiation on the basal-plane conductivity ... of YBa...Cu...O... single crystals is investigated. The excess conductivity ... has been revealed to obey an exponential temperature dependence in the broad temperature range ..., where ... is the transition temperature from the pseudogap state to the regime of fluctuation conductivity. The description of the excess conductivity by the relation ... can be interpreted in terms of the mean-field theory where ... is the mean-field transition temperature to the pseudogap state and ... is satisfactory described within the framework of the BCS-BEC crossover theory. In all, electron irradiation of the YBa...Cu...O... single crystals has been revealed to lead to an expansion of the temperature range of the pseudogap state, thereby narrowing the range of the linear dependence of ... in the ab-plane.