8168 Radial Magnet

o-Optic Kerr Effect 1.The Radial Magneto-Optic Kerr Effect (RMOKE) is a magnetic phenomenon that involves the conversion of electric field energy into rotational kinetic energy for the purpose of studying magnetic materials. 2. It occurs away from the regions of external magnetic field, making it possible to locate the origin of magnetization of a given material at its centre while measuring the radial component of the magnetization. 3. RMOKE is a useful technique for studying magnetic properties of small samples, where the analysis of magnetization with the help of external fields is not possible. 4. It is useful in exploring the interactions between magnetic nanoparticles with their local environment, especially their nearest-neighbor exchanges. 5. For example, nanoscale ferromagnetic structures and their characteristics can be studied using RMOKE. 6. In RMOKE, circularly polarized light is passed through a small, polarized (longitudinal) area in a magnetic medium. 7. The polarization of light is altered by the presence of a linear magnetic field perpendicular to the polarization vector. 8. An external magnetic field is then applied in the same direction and driven by a piezoelectric actuator. 9. The induced magnetization in the sample then produces a change in the signal that can be used to study the physical properties of the material.