Building Magneto Optical Kerr Effect and Magnetic Circular Dichroism Measurement Set Up

The Magneto Optical Kerr Effect (MOKE) measurement is a unique characterization tool to investigate the magnetic property of patterned nanostructures by measuring the modulation in polarization of reflected light from the surface of the magnetic sample. Our MOKE set up has been upgraded to include magnetic circular dichroism (MCD) components to measure both the rotation and ellipticity of the polarization of the reflected light. Upgraded set up also introduces 4f alignment and accommodates computer controlled fast-steering mirror to achieve MOKE/MCD microscopy. Adding 4f alignment for the incident laser beam cleans and focuses the incident beam and filters out the noise to improve the quality of magnetic domain images. Samarium Cobalt (SmCo) nanocap thin films were fabricated by sputtering SmCo layer on top of the closely packed single layer of nano/microsphere template. MOKE measurements performed in different microstructures showed that the nanocap thin films have different magnetic switching behavior compared to flat film due to the magnetic anisotropy developed from the induced curvature in the nanocap thin films. Specifically, the contribution of out of plane magnetization component during the switching was observed and this was measured separately using polar MOKE geometry.