Ultrathin Co/Pt and Co/Pd multilayered films as magneto-optical recording materials

Abstract

Co/Pt and Co/Pd multilayered films were prepared by two-source dc magnetron sputtering. The multilayers with thin Co layers, one to three atoms thick, exhibited a perfect squareness of Kerr loop and an enhancement of Kerr rotation when the total film thickness became below several hundred angstroms. These ultrathin films have a high Kerr rotation of 0.2°-0.45° and strong perpendicular magnetic anisotropy even in the very thin-film thickness. The figure of merit of the ultrathin Co/Pt films is superior to that of TbFeCo system at 780 nm and becomes larger at shorter wavelength. The ultrathin multilayers possess very high corrosion resistance, and the layered structure is thermally stable up to 400 °C. Consequently, the ultrathin Co/Pt and Co/Pd multilayered films can be new magneto-optical recording materials, especially for higher density recording using a shorter wavelength laser.

Comparison of first-principles methods to extract magnetic parameters in ultrathin films: Co/Pt(111)

“…This highlights that a prediction of the Curie temperature of thin films purely from the knowledge of bulk properties is to be taken with caution and possibly fails. Overall, our calculations confirm that the Curie temperature of Co thin-films on Pt(111) lies far above room temperature 61,62 , even for the monolayer.…”

Magnetocrystalline anisotropy in (111)CoPt3thin films probed by x-ray magnetic circular dichroism

“…In this respect, Co/Pt or Co/Pd multilayers, which may exhibit strong perpendicular magnetocrystalline anisotropy ͑PMA͒ and a large Kerr rotation at short wavelengths, have been extensively studied. [1][2][3] Coevaporated Co-Pt thin films have also shown strong PMA with 100% remanence and enhanced MO signals with respect to Co/Pt multilayers. 4 In epitaxial CoPt 3 thin films, PMA was clearly shown to be dependent on the growth temperature.…”

Stacked Pt/Co Multilayers With Independent Control of Coercivity and Curie Temperature

“…This effect was reported by Hashimoto et al [4]. Two 9 period PtxNC03A multilayers were prepared where x = 8 and 15.…”