Effect of Temperature and Magnetic Fields on the Thin-Film dc Superconducting Transformer

Magnetically coupled tin films are found to exhibit the characteristic dc transformer effect first reported by Giaever only for reduced temperatures of the primary $0.925<t<\mathrm{}1\mathrm{}$. A striking dependence of the secondary voltage on magnetic fields is also observed. The temperature dependence of the depinning current and the critical current is discussed.