Effects of magnons on spin transport in ferromagnetic metals

Abstract

In this Thesis, spin-injection from a ferromagnetic to a non-ferromagnetic region is discussed using drift-diffusion theory. This is an important subject in spintronics nowadays where the spin of the electron is used instead of its charge. First, a simple system with a charge current density is presented. Then, spin-injection due to a constant temperature gradient is studied. Magnons are then brought into this system to see what effect they have. The contribution of the magnons is found to be substantial and results in injected spin accumulations that are around 10^2 higher than without magnons. We also study the temperature dependence to see in what temperature regimes magnons and electrons are important. At low temperatures, magnons seems to have the biggest contribution.