Effect of Pt seed on magnetic properties of Co-Pt alloy deposited into aluminum oxide pores

We have deposited a Co-rich hcp Co-Pt alloy into aluminum oxide pores by applying pulse voltage. The Co content in Co-Pt alloy increased with increasing pulse voltage, which was 95% at 7 V. We found that the Pt seed remarkably enhances the perpendicular anisotropy, thus increasing the squareness and coercivity of the perpendicular magnetization curve. The Co-Pt alloy on the Pt seed is randomly oriented, hardly affecting the perpendicular anisotropy due to the shape effect. However, without the Pt seed, the magnetocrystalline anisotropy of the hcp Co-Pt alloy reduces the shape anisotropy significantly. We also found that the Pt seed greatly reduces the amount of Co-Pt alloy deposited.