The effect of the sputtering gas (Ar, Xe) on FePt clusters formation: structural and magnetic properties

It will be reported about the effect of the sputtering gases, Ar and Xe, on FePt clusters formation by magnetron sputtering deposition at high working pressures. All layers, with bulk equivalent thicknesses between 3 to 5 nm, were realized at RT by a sequential layer by layer deposition or a co-deposition of Fe and Pt. After rapid thermal annealing at 500 °C, the highest L10 fraction was found using Xe as sputtering gas: Xe decreases the transformation activation energy and therefore, reduces the critical thickness necessary to obtain the high anistropic ferromagnetic phase. Ar assisted growths lead to FePt clusters in the L10 phase only if the sequential layer deposition is used, whereas for Xe no differences in the deposition techniques were observed.