Room temperature GMR studies in (Cr,Ta)/[Au/NiFe]n multilayers

Multilayered samples of Au/NiFe were sputtered using dc magnetron sputtering, for room temperature giant magnetoresistance (GMR) studies. Two characteristic GMR peaks were observed at 15 and 28 Å of Au spacer thickness, with values of 7.4% and 5.4%, respectively. The large magnetoresistive effect at low applied field has been attributed to the weak antiferromagnetic coupling of the magnetic layers as indicated by their calculated exchange constant values. The effect of a buffer layer on the GMR hysteresis, along with its field sensitivity were investigated for both Cr and Ta precursor layers. The Ta underlayer showed a significantly reduced GMR hysteresis. Also reported are GMR values as a function of applied magnetic field during multilayer deposition, and substrate/buffer layer effects. The multilayer structures were high quality and textured along the ⟨111⟩ direction