Fabrication And Properties Of SmCo/Cu Thin Films

High-density recording systems require thin film media with high anisotropy energy and fine small grains to satisfy the requirement for thermal stability of the recorded data. In particular for longitudinal recording densities above 1TGb/in2, satisfactory SNR require grain size approaching the thermal limit. The limit can be overcome by adopting the magnetic films with higher coercivity. In the respect, rare earth-transition metal alloys SmCo thin films, as they possess the highest anisotropy values, are particularly attractive and make them the best candidates for super-high density recording.In this article, many issues have been studied as following:Studied the limits of the longitudinal area density adopted the theory of basic information storage. Discussed the longitudinal magnetic recording limits, and the decay of signal to noise (SNR) due to thermally induced magnetization fluctuation. Simplified Arrhenius-Neel analysis is utilized to determine limit densities versus for longitudinal recording media. At the same time, we discuss recording medias with high Ku can improve the density.Experimentally, studied a number of as-deposited SmCo/Cu films on glass underlayer produced by RF magnetron sputtering. Using controlled variable method, systemic studied the dependence of magnetic properties of Ar pressure,magnetic layer thickness. And successfully prepared SmCo / Cu thin films with in-plane anisotropy (Hc = 2800 Oe). Cu underlayer can promote the coercive force evidently. Also studied the dependence of Cu underlayer structure of temperature,thickness and power.At last, elementary investigated SmCo/Cu thin films with perpendicular anisotropy. As the results shows, the power of the magnetic layer and the temperature of Cu underlayer will influence the coercive force of SmCo magnetic layer. Prepared the SmCo/Cu thin films with perpendicular anisotropy (Hc = 6025 Oe) successfully.