Real time structural modification of epitaxial FePt thin films under x-ray rapid thermal annealing using undulator radiation

Abstract

Modification of chemical order in epitaxial FePt binary alloy thin films deposited on MgO (100) substrates was induced and investigated in real time using x-ray rapid thermal annealing (XRTA). This is possible because synchrotron undulator radiation has sufficient power density to induce significant structural modifications in thin films and its energy can be tuned to optimize absorption in the sample. A monochromatic portion of the pink beam diffracted from the epitaxial FePt sample was used to probe microstructure evolution in real time and significant changes in chemical order were observed. In particular, the relative amount of L10 phase remained practically unchanged whereas the amount of L12 phase was significantly decreased in the FePt thin film sample during XRTA.