| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 1613567 | Journal of Alloys and Compounds | 2013 | 5 Pages |
•SmCo5 (25 nm)/Fe (8 nm)/SmCo5 (25 nm) trilayers were grown by sputtering.•Effect of annealing on the interphase chemistry was investigated using RBS.•Optimal interphase coupling with good phase chemistry was observed at 773 K.•Enhanced Hc (814 kA/m) and (BH)max (243 kJ/m3) values were achieved at 773 K.
SmCo5/Fe/SmCo5 sandwich configurations have gained renewed interest when compared to the conventional SmCo5/Fe bilayers, as they exhibit enormous scope to impart high energy product values with strong magnetization reversal behavior. The compositional changes that occur in the intermediate soft layer upon annealing play a critical role in determining the phase chemistry, as well as magnetic performance of the trilayers and herein we address such a study. SmCo5/Fe/SmCo5 sandwich films with fixed layer thicknesses of SmCo5 (25 nm) and Fe (8 nm) were grown by sputtering on Cr buffered Si (1 0 0) substrates and subsequently, annealed at different temperatures: 673, 773 and 873 K. The effect of post-deposition annealing on the structure, composition and magnetic properties of the trilayer architecture was investigated by X-ray diffraction (XRD), Rutherford back-scattering (RBS) and super-conducting quantum interference device (SQUID), respectively. The XRD studies showed significant decrease in the lattice parameter values with increasing annealing temperature, which suggests an increase in the diffused Co-content in the Fe-intermediate layer. The XRD results were further validated by RBS measurements, which confirmed that both composition and thickness of the Fe-intermediate layer were strongly affected by the annealing temperature. The SQUID measurements demonstrated the existence of in-plane anisotropy and strong exchange coupling between the hard and soft layers for all the annealed sandwich films. The trilayer stack annealed at 773 K showed the best magnetic performance such as high coercivity (814 kA/m), remanence (944 kA/m) and energy product (243 kJ/m3).
