Carrier concentration induced transformations and existence of pseudogap in NdBa2Cu3O7-δ

Abstract We have studied transport properties of several NdBa 2 Cu 3 O 7-δ   superconductors using wide range of excess oxygen content δ. The buckling angle is found to be very sensitive with δ. Disordered copper oxide planes are origins of the superconducting properties controlling of which is possible by changing the buckling angle in superconducting planes in addition to the carrier concentration. A phase diagram consisting of the characteristic temperature T* related to the formation of pseudogap and critical temperature with δ has been obtained. The effect of the changed buckling angle on the pseudogap formation with δ has been also studied.