Micromagnetic studies on exchange coupled composite recording media

• Published in: Journal of applied physics Vol. 111; no. 7; pp. 07B719 - 07B719-3
• Main Authors: Xie, Hailong, Li, Hongjia, Wang, Ying, Zhang, Kaiming, Wang, Yi, Li, Zhenghua, Bai, Jianmin, Wei, Fulin, Wei, Dan
• Format: Journal Article
• Language: English
• Published: American Institute of Physics 01.04.2012
• ISSN: 0021-8979; 1089-7550
• DOI: 10.1063/1.3679450

The exchange between the hard and soft layer in the exchange coupled composite (ECC) medium is crucial for the recording performance. An accurate micromagnetic model is built for Co-TiO 2 (4 nm)/Pt( δ =0−2.8 nm)/CoPt-TiO 2 (16 nm) ECC media, based on the microstructure, to investigate the magnetic parameters such as the exchange constant A * 3 between the soft/hard layer. In the M-H loops of CoPt-TiO 2 (16 nm) hard layer, the perpendicular coercivity is 6.1 kOe and the squareness S is 0.98. In ECC media, the thickness δ of interlayer Pt has comprehensive effects on magnetic properties: the coercivity and squareness change little when we just vary A * 3 or δ ; A * 3 equals the intragrain exchange constant A * 1 when δ is thinner than grain boundary (≤2 nm); and A * 3 decreases from the intergrain exchange constant A * 2 to 0 when δ increases from 2.2 to 2.8 nm. The simulation results agree well with experiments.