xiii, 110 p. A print copy of this thesis is available through the UO Libraries. Search the library catalog for the location and call number. / This dissertation investigates the interplay between, and the possible coexistence of, magnetic and superconducting order in metals. We start with studying the electromagnetic properties of s-wave superconductors near a ferromagnetic instability. By using a generalized Ginzburg-Landau theory and scaling arguments, we show that competition between magnetic order and superconducting order can change the scaling of observables. For instance, the exponent for the temperature dependence of the critical current can deviate from the Ginzburg-Landau value of 3/2. These results may be relevant to understanding the observed behavior of MgCNi 3 . We then study the nature of the superconductor-to-normal-metal transition in p-wave superconductors. Although the phase transition is continuous at a mean- field level, a more careful renormalization-group analysis in conjunction with large-n expansion techniques strongly suggest that the transition is first order. This conclusion is the same as for s-wave superconductors, where these techniques also predict a first-order transition. In p-wave superconductors, topological excitations known as skyrmions are known to exist in addition to the more common vortices. In the third part of this dissertation, we study the properties of skyrmion lattices in an external magnetic field. We propose iv experiments to distinguish vortex lattices from skyrmion lattices by means of their melting curves and their μSR signatures. / Adviser: Dietrich Belitz

<p> It is believed that Sr2RuO4 is a triplet superconductor that breaks time reversal symmetry, and it is expected to have spontaneous magnetization both at the sample edge, as well as at domain walls. Recent magnetic microscopy results place upper limits on the magnetic fields differing from previous theoretical calculations by 2 orders of magnitude. Using a Ginzburg-Landau formalism we investigate the effects of a rough surface as well as parameter choices which differ from the typical weak coupling parameters on the magnitudes of the spontaneous supercurrents and magnetic fields. The dependance on surface roughness is found to be small resulting in only a 20% reduction for the weak coupling parameters. Changing the parameters from weak coupling in addition to pair breaking surface effects is also found to affect the magnitudes of the spontaneous fields weakly, except in certain unphysical parameter regimes. The effects of the surface stabilizing another non-magnetic order parameter are considered, and give rise to field distributions with similar features to those present at domain walls.</p> / Thesis / Master of Science (MSc)