ISSN:
1089-7550
Source:
AIP Digital Archive
Topics:
Physics
Notes:
Co-Re metallic superlattices were prepared that show antiferromagnetic exchange coupling and enhanced saturation magnetoresistance for particular values of the Re spacer thickness. We report studies on films with the structure glass /150 A(ring) Re/[13 A(ring)Co/tRe]16/50 A(ring) Re, with tRe ranging from 3 to 40 A(ring). These structures were grown by magnetron sputtering in a system with a base pressure of 1×10−7 Torr with deposition rates of 0.3 and 0.4 A(ring)/s for Co and Re, respectively. x-ray diffractograms indicate the structure to be highly textured with the c axis perpendicular to the sample plane. The superlattice structure was obtained from high-angle θ-2θ scans. First-, second-, and third-order satellites are observed on both sides of the central [002] peak. Periodicity and bilayer composition are obtained from comparison of the data with a theoretical calculation of the x-ray diffractogram. Thickness calibration was confirmed by Rutherford backscattering and profilometer data. In-plane magnetization and magnetoresistance data (Δρ/ρ) indicate that stronger antiferromagnetic coupling and highest Δρ/ρ occur for tRe≈6 A(ring). The saturation field (Hs) needed to align contiguous antiferromagnetically coupled Co layers is about 1 T. This corresponds to an exchange coupling between the Co layer J≈−1 erg/cm2. (Δρ/ρ) reaches 2% in samples deposited at 170 °C. This data confirms results obtained by Parkin et al.1 in Co-Ru and Co-Cr superlattices.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1063/1.350116
