Spin curvature induced resistivity in epitaxial half-metallic CrO2 thin films
Spin configuration inside a ferromagnetic metal influences its magnetoresistive behavior. Local spin curvature induces excess resistivity from the homogenous ferromagnetic state. In this work, we characterize the spin curvature induced resistivity in epitaxial half-metallic CrO2 nanowires with 100% spin polarization. We control the magnitude of spin curvature by introducing different geometric notches along the edge of the wire and applying external magnetic field. Through magnetoresistance measurement and micromagnetic simulation, we uncover an empirical relation between the spin curvature and the induced resistivity in this archetype half-metallic solid. This relation provides a quantitative method to calculate resistance of magnetic domain walls or other spin textured states. We also study the thermal effect on the spin curvature induced resistivity across temperature range from 10K to 250K. Thermal magnons worsen spin asymmetry effectively and suppress spin curvature induced resistivity at temperatures much lower than the ferromagnetic ordering temperature Tc.