Magnetotransport and magnetic properties of amorphous NdNi 5 thin films

Abstract

Abstract: NdNi5 is an intermetallic compound with a bulk Curie temperature (TCurie) of 6–13 K. While existing studies have focused on NdNi5 crystals, amorphous thin-films of NdNi5 are potentially important since they would be magnetically soft without magnetocrystalline anisotropy, meaning that small external magnetic fields could reverse the direction of their magnetization. Here, we report NdNi5 thin-films with a thickness in the 5–200 nm range, deposited by DC magnetron sputtering onto Si(100). Films are amorphous with a weak temperature-dependent resistivity with values ranging between 150 and 300 μΩ cm. By means of noise spectroscopy, by analyzing the time-dependence of fluctuation-induced voltages, it is found that at low temperatures the resistance fluctuations are due to the Kondo effect. Volume magnetometry indicates TCurie=70 K with a magnetic coercive field of 30 mT at 5 K for a 125-nm-thick film. The results are promising for the development of Ferromagnet(F)/Superconductor(S)/Ferromagnet(F) pseudo spin-valve devices based on amorphous NdNi5 thin films.