Post-deposition annealing was performed on trilayer films consisting of a C overcoat layer on top of CoCrPt/CrTi/glass substrate. We observed a coercivity of 3600 Oe in the films with a 4nm Covercoat, which was about three times larger than the coercivity of similar films without a Covercoat. This is most likely due to the significant decrease in intergranular exchange coupling for the films with Covercoat, as shown by the annealing treatment. It is believed that the diffusion of C into CoCrPt grain boundaries promotes magnetic grain isolation.

Temperature dependence of the properties of RE-TM thin films is very important for MO recording. In this paper, we studied the temperature dependence of the magnetic and magneto-optical properties of the amorphous LRE-HRE-TM single layer thin films and LRE-HRE-TM/HRE-TM couple-bilayered thin films. For LRE-HRE-TM single layer thin films, the temperature dependence of the magnetization was investigated by using the mean field theory. The experimental and theoretical results matched very well. With the LRE substitution in HRE-TM thin film, the compensation temperature Tcompdecreased and the curie temperature Tc remained unchanged. Kerr rotation angle became larger and the saturation magnetization Ms at room temperature increased. For LRE-HRE-TM/HRE-TM couple-bilayered thin films, comparisons of the temperature dependences of the coercivities and Kerr rotation angles were made between isolated sublayers and couple-bilayered thin film.

Abstract-A sequence of magnetic-optical ternary DyFeCo and quaternary SmDyFeCo films have been prepared by r.f. magnetron sputtering method. The magnetic, magneto-optical and temperature property of quaternary SmDyFeCo films was invcstigatcd comparcd with the ternary DyFeCo films. The results show that SmDyFeCo films have good reproducibility. The writing/erasing cycles of the SmDyFeCo films was estimated over 10 6 times.

Abstract-The introduction of the Cr interlayer caused magnetic decoupling in SmCoAlSi/Cr/SmCoAlSi and SmCoAlSi/Cr/SmCoCuTithin films. High coercivity of 3400～3840 Oe and extremely fine grain size in this two kinds of films were examined. Magnetic coupling within sublayers was introduced by using different substrate bias among the SmCoAlSi (deposited with substrate bias of-150 V)/SmCoAlSi(deposited with no substrate bias)/SmCoAlSi(deposited with substrate bias of -150V) triple layers. This multilayer exhibited high coercivity～2960 Oe and S* 0.96. SmCoAlSi/ SmCoCuTi/SmCoAlSi trilayer improved matching between the magnetic layer and the Cr underlayer, and led to increased in-plane anisotropy, high coercivity 3620 Oe and S* 0.91. The microstructures of these four kinds of media were also examined. Results obtained suggest that it is possible to produce SmCoAlSi-based multilayer media with the combined magnetic properties requied for the ultra-high magnetic recording density of～20 Gbit/in2.

Smxco100-x(20≤x≤30)films deposited on glass substrate and Sm37.8Co62.2 films deposited on silicon substrate with perpendicular magnetization have been prepared by a magnetron rf sputtering. The influence of sputtering conditions, I.e. bias voltage; substrate temperature; composition and perpendicular magnetic field on perpendicular anisotropy are reported in detail.