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Magnetic imaging of superconductors typically requires a soft-magnetic material placed on top of the superconductor to probe local magnetic fields. For reasonable results the influence of the magnet onto the superconductor has to be small. Thin YBCO films with soft-magnetic coatings are investigated using SQUID magnetometry. Detailed measurements of the magnetic moment as a function of temperature, magnetic field and time have been performed for different heterostructures. It is found that the modification of the superconducting transport in these heterostructures strongly depends on the magnetic and structural properties of the soft-magnetic material. This effect is especially pronounced for an inhomogeneous coating consisting of ferromagnetic nanoparticles.

Non-uniform illumination of solar cells leads to a decrease in efficiency. Two cases were investigated experimentally: loss of power due to the shadowing of a fringe area of one cell, and loss of output of two cells which were connected in series and were illuminated to different degrees. The results show that losses due to these effects will reduce the output of concentrator photovoltaic systems working at low concentration conditions by a few per cent only.