Date of this Version
IEEE Transactions on Magnetics 49:7 (July 2013)
Films of L10-structure Fe50–xCoxPt50 films are synthesized by co-sputtering Fe, Co, and Pt on (001) MgO substrates and Si substrates with in-situ heating at 830°C. The nanostructures and magnetic properties of the films are characterized by X-ray diffraction, transmission electron microscopy, and SQUID. The compositions of the samples Fe50–xCoxPt50 are designed to maintain an atomic (Fe+Co):Pt ratio of 50:50 while increasing the Co content in each successive sample. In all samples, the X-ray diffraction patterns from samples on MgO substrate exhibit three strong peaks, namely L10Fe50–xCoxPt50 (001), (002), and MgO (002). The X-ray and electron diffraction patterns from untextured samples deposited on Si substrates can be indexed using the L10-structure, being consistent with the result of samples on MgO substrate. Hysteresis-loop measurements show that with increase of the Co concentration from 0 to 15 at%, the saturation magnetization Ms increases from 1017 emu/cm3 to 1165 emu/cm3, the coercivity decreases from 30 kOe to 14 kOe, and anisotropy decreases from 67 Merg/cm3 to 46 Merg/cm3. The nominal maximum energy products are in the range of 39–41 MGOe.