UC Irvine

This thesis describes three experiments in the topics of magnetism and superconductivity. The first experiment demonstrates the ability to have magnetic control of the triplet component amplitude in a Nb/Co/Cu/Co/CoO superconducting spin valve. The experiment is done by measuring the superconducting transition temperature, Tc, in the multilayers as a function of the angle alpha between the magnetic moments of the Co layers. The measurements reveal that Tc(alpha) is a nonmonotonic function, with a minimum near alpha = pi/2. The experimental data were compared with numerical self-consistent solutions of the Bogoliubov--de Gennes equations calculated by our collaborators. This thesis shows that experimental data and theoretical evidence agree in relating Tc(alpha) to enhanced penetration of the triplet component of the condensate into the Co/Cu/Co spin valve in the maximally noncollinear magnetic configuration. The second experiment is a crystallographic characterization of a magnetron sputtered IrMn3 thin film which is a metallic non-collinear antiferromagnet. It has been predicted to have a large anomalous Hall effect, which enables magnetic state readout in antiferromagnetic spintronic devices. The third experiment is a demonstration of unusual magneto-dynamic phenomena in nanoscale ferromagnets due to resonant three-magnon scattering. In this work, some numerical calculations are presented of a theory made by a collaborator.