Transport Properties of Cu/Permalloy Artificial Layers

Abstract

We have measured the electrical resistance R of wires and foils of thin artificial Cu/Permalloy (NiFe) layers in the temperature range from 0.1 K to 200 K under magnetic fields up to 10 tesla, and the thermoelectric power S from 2 K to 200 K. The logarithmic increase of R in the low temperature range (below 20 K for example) was observed for all the present samples. This increase of R was found to stay unchanged even under a strong magnetic field of as much as 10 tesla. The curves of S as a function of temperature T showed a normal metal behavior without any Kondo type anomaly. Possible origins of the logarithmic increase of R are discussed.