Magnetic properties and microstructure of perpendicular FePt(B-Ag) granular films

Multilayers [FePt(1 nm)/(BxAg1-x)(0.1 nm)](10) (x = 0 - 1) were alternately deposited on a glass substrate and subsequently annealed by a rapid thermal process (RTP) at 800 degrees C for 3 min. After RTP, FePt and immiscible (B, Ag) layers intermix to form (FePt)(90)(B-Ag)(10) granular. The intermixed (B, Ag) atoms with high mobility diffuse among FePt grain boundaries to isolate and refine FePt grains uniformly with average grain size of 10 - 12 nm. The c-axis alignment in original multilayers remains unaltered during intermixing. With increasing Ag content in (BxAg1-x) (x = 0.3 - 0.7), c-axis orientation and grain-refinement are further improved. The optimal composition is (Fe0.48Pt0.52)(90)(B0.7Ag0.3)(10). (C) 2012 American Institute of Physics. [doi:10.1063/1.3672860]