Phase-Change Magnetic Memory: Rewritable Ferromagnetism by Laser Quenching of Chemical Disorder in Fe60Al40 Alloy

In magnetic data storage, information can be corrupted by external magnetic fields or thermal fluctuations. A possible solution to both problems is reversibly altering the $m\phantom{\rule{0}{0ex}}a\phantom{\rule{0}{0ex}}g\phantom{\rule{0}{0ex}}n\phantom{\rule{0}{0ex}}i\phantom{\rule{0}{0ex}}t\phantom{\rule{0}{0ex}}u\phantom{\rule{0}{0ex}}d\phantom{\rule{0}{0ex}}e$, rather than direction, of a bit's magnetization. The authors propose such an alternative memory, based on chemical-order--disorder transformations in thin-film Fe-Al alloys where cycling (writing--erasing--writing) of disorder-induced ferromagnetism is found to occur under short-pulse heat treatments, e.g. laser irradiation, employed in information recording and storage technologies.