Intermediate states of superconducting thermometers for x-ray   microcalorimeters
  Intermediate states near normal-superconducting transition at ~100mK, important for a sensitive thermometer in x-ray calorimetry, have been studied by an imaging technique based on Low Temperature Scanning Synchrotron Microscopy (LTSSM). In conjunction with iridium superconducting transition-edge sensors operating in electrothermal feedback mode, the LTSSM visualizations reveal that a normal-superconducting phase separation takes place in the actual intermediate states. 
H. Pressler, M. Koike, M. Ohkubo, D. Fukuda, Y. Noguchi, M. Ohno, H.   Takahashi, M. Nakazawa