Perpendicular magnetic anisotropy in Ta/Pd/Co2FeAl0.5Si0.5/MgO/Ta structured films

In this work, the perpendicular magnetic anisotropy (PMA) was realized in Ta/Pd/Co2FeAl0.5Si0.5/MgO/Ta films, but not observed in Ta/Pd/Co2FeAl0.5Si0.5/Ta films without MgO cap layer. A strong PMA had been achieved for a thick Co2FeAl0.5Si0.5 layer about 4.8 nm at the annealing temperature of 300 °C. Inserted Pd layer between Ta and Co2FeAl0.5Si0.5 layers was crucial to obtain PMA in Ta/Pd/Co2FeAl0.5Si0.5/MgO/Ta structured films. However, the thickness of inserted Pd layer has no significant effect on the value (Keff) of PMA. The films annealed at 300 °C remain a similar Keff of around 1.23×106 erg/cm3 while the inserted Pd layer is beyond a critical thickness.