Suppressing FePt order-disorder structural phase transition temperature by Ag doping: First principles investigation for enhancing magnetic recording density

Abstract

ABSTRACTIn this work, we used density functional theory to study the structures, formation energy and order–disorder structural transition temperature (To) of L10 FePt with Ag additive. The results show that an Ag atom substituting for a Fe site is more energetically preferable than that of substituting for a Pt, thus Ag atom should replace Fe site. We found that To is significantly suppressed by Ag impurity because of the increasing in configurational entropy, whereas the magnetism tends to decrease due to the absence of some Fe atom in doping processes. The decrease in To could open the opportunity to prepare FePt with lower temperature and small grain size for the high density magnetic recording media application.