Date of this Version
AIP ADVANCES 6, 056010 (2016)
Different thicknesses of FePt/Fe bilayer films are deposited on (001) MgO substrates by sputtering Fe and Pt targets with in-situheating at 830°C. X-ray diffraction indicates a complete alignment of the FePt  axis with MgO  axis. The nucleation field Hn is estimated from hysteresis loops measured using a SQUID magnetometer. A FePt/Fe bilayer model is proposed to calculate the nucleation field Hn and compared with the experimental data. The model can explain experimental trends and gives useful predictions for nanostructure synthesis and further experiment.