Effect of Underlayer Structures on Microstructures and Magnetic Properties of Co-Rich Co-Pt Films Prepared at Ambient Temperature

• Published in: IEEE transactions on magnetics 2014-07, Vol.50 (7), p.1-4
• Main Authors: CHEN, Sheng-Chi, SUN, Ta-Huang, WANG, Chung-Hsien, CHIOU, Jie-Yang, CHEN, Shang-Tse, KUO, Po-Cheng, CHEN, Jiann-Ruey
• Format: Article
• Language: English
• Subjects: Ambient temperature; Argon; Coercive force; Cross-disciplinary physics: materials science; rheology; Deposition; Exact sciences and technology; Grain size; Magnetic anisotropy; Magnetic properties; Magnetism; Materials science; Nanostructure; Other topics in materials science; Perpendicular magnetic anisotropy; Perpendicular magnetic recording; Physics; Silver; Surface layer; Texture
• ISSN: 0018-9464; 1941-0069
• DOI: 10.1109/TMAG.2013.2297731

Granular Co-rich Co-Pt nanograins having perpendicular coercivity (Hc ⊥ ) of 4.0 kOe and perpendicular squareness (S ⊥ ) of 0.75 can be achieved by depositing Co 80 Pt 20 (25 nm) film onto Ru (30 nm)/Ag (100 nm) bilayer films using an argon pressure of 5 mTorr to deposit an Ag underlayer at ambient temperature. However, it is found that the Co 80 Pt 20 film deposited directly onto an Ru layer without an Ag underlayer shows in-plane magnetic anisotropy. This is because an fcc Ag (111) underlayer can enhance the hcp Ru (0002) seed layer, inducing (0002) texture in the hexagonal Co 80 Pt 20 magnetic layer, leading to the perpendicular magnetic anisotropy of Co 80 Pt 20 films. TEM images show that granular nanograins with an average size of 8.0 nm can be observed in the Co 80 Pt 20 magnetic layer.