High Perpendicular Magnetic Anisotropy of CoPtCr/Ru Films for Granular-Type Perpendicular Media

Abstract

The perpendicular magnetic anisotropy of CoPtCr films deposited on Ru seed layers is discussed as a function of film composition. Moreover, the change in by the addition of SiO 2 is examined in light of thermal stability of CoPtCr-SiO 2 media. The of Co-10 at % Cr shows a high value of 5 10 6 erg cm 3 , which is much higher than that reported by Bolzoni et al. The addition of Pt to the Co-10 at % Cr film results in a further enhancement of . A maximum of nearly 10 10 6 erg cm 3 is observed at 25 30 at % Pt. All series of films with various Cr contents show maximum values of at 25 30 at % Pt. The maximum value for CoPt (Cr = 0) films reaches 15 10 6 erg cm 3 . The value of magnetocrystalline anisotropy of grains, calculated by taking account of the volume fraction of CoPtCr grains, decreases as the SiO 2 content increases. However, the maintains a large value of more than 7 10 6 erg cm 3 , even at 10 at % SiO 2 in addition to (Co 90 Cr 10 ) 80 Pt 20 , which indicates a high potential of CoPtCr-SiO 2 media to resist thermal agitation of magnetization.Index Terms-CoPtCr films, CoPtCr-SiO 2 media, perpendicular magnetic anisotropy, Ru seed layer, thermal agitation of magnetization.

Magnetization process of high anisotropy CoPt nanosized dots

“…Co Pt films of 20 nm in thickness are deposited with Ru(20 nm)/Pt(10 nm)/Ta(5 nm) buffer layers on a thermally oxidized Si substrate by magnetron cosputtering at room temperature [3]. The hcp-CoPt (002) plane is epitaxially grown on the (002) plane of the Ru buffer layer, which is grown parallel to the film plane.…”

“…In this paper, we present the result of AHE measurements on nanosized dot arrays made of Co Pt alloy film with large perpendicular anisotropy [3] and discuss the magnetization reversal process.…”

Fabrication of 1 Tdots/in2 Patterned Media with Anodic Alumina Technique

“…This layered structure was adopted to obtain c-axis orientation of the hcp-Co70Pt30 continuous film. [11] 5. Characterization of 1 Tdots/in 2 patterned media images of low and high magnification, respectively.…”

Magnetocrystalline anisotropy of magnetic grains in Co80Pt20:oxide thin films probed by x-ray magnetic circular dichroism

“…This result is critical as it suggests that there is a limit for the areal density capability caused by the dilemma between the simultaneous requirements for small grain size and large K 1g . The value of K 1g is usually calculated from the magnetocrystalline anisotropy of the media, K 1 , by taking account of the OVF 5,6 . However, a direct observation and accurateexperimental determinationon the magnetic properties and anisotropies of the magnetic grains is lacking and necessary.…”