Neutron diffraction by the flux line lattice in YBa2Cu3O7−δ single

Abstract

Small angle neutron diffraction was used to image the mixed state in a large twinned superconducting Y-123 single crystal. The integrated intensity I10 of the (10)-reflection was evaluated as a function of temperature and used to derive λ(T) on an absolute scale, which provides us with information on the nature of the pairing mechanism. The results are compared with theoretical predictions calculated within the framework of BCS-theory or other approaches such as d-wave pairing.