Promotion of L10 ordering of FePd films with amorphous CoFeB thin interlayer

The L1(0)-ordered FePd thin films were prepared using an ultrahigh vacuum magnetron sputtering system on MgO(001) substrates at 300 degrees C. The crystallographic and magnetic properties and the surface morphology of films with and without a very thin amorphous CoFeB intermediate layer inserted between the FePd and the MgO layers were systematically investigated as a function of the thickness of the FePd layer. The perpendicular anisotropy of the samples was increased by inserting the thin CoFeB as an intermediate layer below the FePd with a thickness of 4.0 nm. The reason for the enhancement by inserting the amorphous CoFeB layer is attributed to: (i) the promotion of the L1(0) ordering of the FePd due to the reduction of the lattice mismatch between the MgO and FePd, and (ii) the fact that thin CoFeB has a perpendicular anisotropy at the interface of the MgO, which superposed the perpendicular anisotropy of the L1(0)-FePd. (C) 2012 American Institute of Physics. [doi:10.1063/1.3673409]