Interplay of superconductivity, magnetism, and localization in Mo/Ni superlattices

A new experimental relationship between superconductivity, magnetism, and localization is explored in short-wavelength ($14\AA <~\Lambda <~40\AA$) sputtered Mo/Ni superlattices. A crossover to a superconducting state is observed for $\Lambda <9\mathrm{}$ Å implying paramagnetic behavior when the Ni strata are four atomic layers thick, or less. All samples show localization effects at liquid-helium temperatures and nonsuperconducting samples develop an unusual resistance plateau below $T\approx 0.5$ K.