Hosted by: Lijun Wu

The orientation of spin assemblies in ferromagnetic thin films and nanostructures can take a variety of shapes depending on the relative strength of factors contributing to their magnetic free energy. These factors are derived from the direct quantum mechanical exchange between the electronic spins or those mediated by impurities, and those associated with the size, shape, crystallographic structure, strain, dipolar interactions and external fields. Here we present three cases where the orientational dynamics has been studied as functions of temperature, magnetic field strength and the elapsed time after acquiring a particular configuration. These studies are based on magnetic force microscopy and bulk magnetometry measurements on strain epitaxial films of La0.67Ca0.33MnO3, and lithographically patterned submicron size ring assemblies of permalloy and Co/Pd multilayers, which also form artificial spin ices. Towards the end of this lecture we will discuss interface driven magnetic and electronic phenomena in magnetic thin films.