L1(0) Ordering of FePtB Films on a Thin MgO Layer

Abstract

A strong perpendicular magnetic anisotropy is obtained in MgO/FePtB/Ti films. After high-temperature (600 degrees C) annealing, an amorphous FePtB layer on a thin polycrystalline MgO layer is transformed into an L1(0) ordered phase with a long range ordering parameter of 0.9 and an effective magnetic anisotropy of 1.29 x 10(7) erg/cm(3). The depth profile of the atomic concentration reveals that the Ti capping layer absorbs boron from the FePtB layer during the annealing. The high-resolution electron microscopy analysis shows that the crystallized FePtB layer has an epitaxial relationship with the underlying MgO layer. (C) 2011 The Japan Society of Applied Physics