We present the dependence of the magnetostriction in Ni 0.8 Fe 0.2 films on Tb and Gd doping concentration and compare with the measured doping dependence of the high-frequency damping. While the magnetostriction and the high-frequency damping are correlated, the dependence is complicated. In particular, the high-frequency damping parameter ␣ increases rapidly (␣ ϭ0.008-0.84) with a modest increase in the magnetostriction ͑ s ϭϪ0.6ϫ10 Ϫ6 to 5.7ϫ10 Ϫ6 ͒ for Tb doping concentrations up to 10%. For Gd doping, the high-frequency damping changes slowly ͑␣ϭ0.008 -0.02͒ as the doping concentration is increased to 10%, whereas the increase in magnetostriction is similar to that observed in the Tb-doped films. Further, it is possible to achieve low magnetostriction ( s ϭ2ϫ10 Ϫ6 ) near the region of critical damping. Measurements of the angular dependence of the ferromagnetic resonance linewidth in Tb-doped Ni 0.8 Fe 0.2 films show little change similar to the behavior observed in undoped Ni 0.8 Fe 0.2 films, although the linewidths are considerably larger. This is in contrast to systems such as Ni 0.8 Fe 0.2 on NiO, which have a large angular dependence indicating that the relaxation process proceeds through the generation of spin waves. The enhanced damping in the Tb-doped films appears, therefore, to be mediated through direct phonon generation.

Studies and implications of the Hall effect in superconducting and semiconducting YBa2Cu3O7−δ thin films J. Appl. Phys. 78, 6658 (1995); 10.1063/1.360486 Nonresonant microwave absorption studies of surface passivation of superconducting YBa2Cu3O7−δ thin films Appl.

We report noise data for discontinuous Ni82Fe18/Ag multilayer test structures. Examination of the noise data for this material indicates that random telegraph fluchator (RTF) noise of the resistance is the predominant noise source. Analysis of the RTF noise in these structures presents an opportunity to estimate magnetic domain or magnetic cluster strengths and the domain-domain interactions.

Thermally activated hopping of a single Abrikosov vortex has been investigated for a thin Pb film that was decorated with an artificial pinning structure. To determine the location of the vortex, the Pb film is fabricated to be one electrode of a cross-strip superconductor/normal-metal/insulator/superconductor (SNIS ) Josephson junction. Distortions in the Fraunhofer pattern specify the vortex location. As the temperature is raised toward T" the vortex depins from the artificial pinning site and reproducibly moves through the same sequence of other pinning sites before it leaves the junction area of the Pb film. The first thermal depinning occurs when the order parameter of the bulk superconductor is about 20%%uo of the T =0 value. The trajectory is not random.

We have measured interface transport in thin-film YBa2Cu3O7−δ /Ag interfaces having resistivities ranging from 10−8 to 10−3 Ω cm2. Analysis of the interface I-V data indicates that tunneling is the predominant transport mechanism even for the in situ interfaces having contact resistivities of 1–7×10−8 Ω cm2. Zero-bias conductance peaks are also observed for the entire range of interface resistivity. The similarity of the zero-bias conductance peaks among these widely varying interfaces suggests that the low-temperature interface transport is governed by the same mechanism in each case. These conductance peaks are analyzed in the framework of the Appelbaum–Anderson model for tunneling assisted by magnetic scattering from isolated magnetic spins in the interface.