Effect of Pd Buffer and Interlayer on the Magnetic Properties of CoCrPt-Oxide Granular Thin Films

Morphostructural and magnetic properties of CoCrPt-oxide (TiO
₂
, CoO) granular thin films deposited on Pd(y)/Ru/Pd(x)/NiTa intermediate layer have been investigated as a function of the Pd thickness (x = 5 and 10 nm; y = 1,3, and 5 nm). The Pd(x) buffer layer shows an fcc (111) texture that leads to a gradual improvement of both the Ru and CoCrPt hcp (0002) crystallographic orientations while increasing the Pd thickness. This results on a significant enhancement of both the effective magnetic anisotropy (K
_eff
= 4.1×10
⁶
erg/cm
³
) and out-of-plane coercivity (H
_c⊥
= 5.7 kOe) with respect to the reference CoCrPt-oxides/Ru/NiTa sample (K
_eff
= 3.4 × 10
⁶
erg/cm
³
, H
_c⊥
= 4.7 kOe) when a 10 nm-thick Pd buffer is used. The inclusion of a Pd(y) intermediate layer between Ru and Co leads to an increase of the effective anisotropy (up to 4.1 × 10
⁶
erg/cm
³
for y = 5 nm) with respect to the reference sample, which can be ascribed to a combined effect of an interface contribution and a term arising from a CoCrPt lattice distortion.