Ordering enhancement of FePt thin films by introducing mo layers

Single-layer FePt, bilayer Mo/FePt and FePt/Mo, and trilayer Mo/FePt/Mo samples were prepared by rf magnetron sputtering. Each layer of FePt and Mo in the studied samples is 20 nm in thickness. Samples were deposited onto corning 1737 glass substrate at room temperature, then annealed at 350 degrees C and 400 degrees C for a period of 10-120 min. Coercivities of the Mo-layer introduced samples were higher than those of single-layer FePt. X-ray diffraction data also indicate higher degree of ordering for Mo-layer introduced samples. We suggest that the incoherent FePt/Mo interface may induce extra nucleation sites for ordering transformation, thus lower the threshold of ordering temperature.