Investigation of weak link microstructure by modulated resistance techniques

We have presented a complete set of MMR and TMR responses, including the new technique of temperature modulated microwave absorption, on a thin film sample of BSCCO on ZrO2. We show that even though the large magnetic field dependence of weak links can, in general, result in a separate weak link MMR response, in addition to any intrinsic response, the TMR response discriminates against weak links in the absence of non-bolometric effects. These four techniques, two global and two local, provide valuable information about the quality of superconducting materials, especially thin film specimens, not easily obtained by other means. Work is in progress to quantify the methods so that relative amounts of intrinsic and weak link material can be obtained. (orig.)