Abstract by Colby Walker
Physics and Astronomy
Exchange bias in [Co/Pd] / IrMn thin films
The material we are studying is [Co/Pd] / IrMn, a combination of a Co/Pt multilayer and an IrMn alloy. This material exhibits a special property called exchange bias. The exchange bias occurs when the sample is field cooled (FC) below its blocking temperature. Once it is field cooled, the material exhibits a horizontal shift, or bias, in the hysteresis loop. This bias is the physical manifestation of exchange coupling interactions between the Co/Pt and the IrMn layers. These measurements are carried out at BYU using a vibrating sample magnetometer (VSM) where we cool the material with liquid helium while applying a large magnetic field. Ultimately, we want to investigate whether coherent X-ray radiation can significantly alter the exchange bias. We plan on carrying these measurements in April using synchrotron radiation, at the Advanced Photon Source (APS).