NiW/Ru underlayer for CoPt-SiO2 granular perpendicular recording media

Area of Science:

• Materials Science
• Thin Film Technology
• Nanotechnology

Background:

• Improving the texture of Cobalt-Platinum (CoPt) thin films is crucial for high-density magnetic recording media.
• Traditional Ruthenium (Ru) underlayers face limitations in promoting desired crystal orientations.
• The need for enhanced magnetic grain isolation and uniform grain size is paramount for data storage performance.

Purpose of the Study:

• To investigate the efficacy of a Nickel-Tungsten (NiW)/Ruthenium (Ru) underlayer as a replacement for a single Ru underlayer.
• To promote the hexagonal close-packed (hcp) (0002) texture in CoPt films.
• To enhance magnetic grain isolation and achieve uniform grain morphology in CoPt-SiO2 recording layers.

Main Methods:

• Fabrication of a face-centered cubic (fcc) (111) textured NiW film.
• Utilizing the NiW film as an underlayer beneath the Ru layer.
• Characterization of the resulting CoPt-SiO2 recording layer's texture, grain size, and magnetic properties.

Main Results:

• The NiW/Ru underlayer successfully induced the desired Ru hcp (0002) texture.
• Enhanced magnetic grain isolation was observed in the CoPt-SiO2 recording layer.
• Uniform grains with sizes below 10 nm were generated.
• The out-of-plane coercivity of the CoPt film was significantly enhanced.

Conclusions:

• The NiW/Ru underlayer is an effective strategy for promoting CoPt hcp (0002) texture.
• This approach leads to improved magnetic grain isolation and uniform grain structure.
• The enhanced coercivity suggests potential for higher performance in magnetic recording applications.