Microstructures and Magnetic Properties of CoPt-C Nanogranular Films

Abstract:

CoPt-C films were fabricated on silicon substrate by dc reactive magnetron sputtering followed by vacuum annealing. The effects of C additions and annealing temperature on the microstructure and magnetic properties were investigated. The as-deposited films had flat, compact surfaces and face-centered cubic structure, which transforms into the face-centered tetragonal structure after thermal annealing at 700°C for 1 hour. The grain size of CoPt increased with the annealing temperature but decreased with increasing C content. No carbide appearing, the C content exists in amorphous state in the nanocomposite films, and it is homogeneous distributed between the CoPt nanograins, which have the benefit to restrain grain growth and obtain isolated CoPt particles with uniform size. The fct-CoPt films annealed at 700°C exhibited high in-plane coercivity, up to 4200 Oe at room temperature and better square degrees. In the CoPt-C granular films, the best doping amount is about 35 at.% C. These CoPt-C films with novel embedded structure and moderate coercivity have shown promise for high density magnetic recording medium.

• Periodical: Key Engineering Materials (Volume 727)
• Pages: 985-990
• DOI: https://doi.org/10.4028/www.scientific.net/KEM.727.985
• Online since: January 2017
• Authors: Lei Ma, Mu Fen He, Gang Cheng, Zheng Fei Gu
• Keywords: CoPt Thin Films, Magnetic Recording, Magnetron Sputtering

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