Magneto-optical recording on evaporated Co/Pt multilayer films

• Published in: IEEE transactions on magnetics 1990-09, Vol.26 (5), p.1700-1702
• Main Authors: Lin, C.-J., Do, H.V.
• Format: Article
• Language: English
• Subjects: Applied sciences; Coercive force; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Disk recording; Exact sciences and technology; Magnetic films; Magnetic hysteresis; Magnetic materials; Magnetic multilayers; Magnetooptic recording; Metals. Metallurgy; Optical properties and condensed-matter spectroscopy and other interactions of matter with particles and radiation; Perpendicular magnetic anisotropy; Physics; Remanence; Temperature
• ISSN: 0018-9464; 1941-0069
• DOI: 10.1109/20.104497

Co/Pt multilayers composed of 0.3-nm Co and 1-nm Pt layers were prepared by e-beam evaporation from Co and Pt sources. These Co/Pt multilayers with a total film thickness of 20-30 nm have a large perpendicular magnetic anisotropy, a perpendicular hysteresis loop with a saturated remanence, a coercivity of about 1.8 kOe, and a Curie temperature of about 300 degrees C. They are structurally stable enough for thermomagnetic magnetooptical recording. Moreover, these Co/Pt multilayers are corrosion resistant and have enhanced Kerr rotation at short wavelengths. On a disk of 15*(Co(0.32 nm)/Pt(1.15 nm)) multilayer enhanced with 80-nm silicon nitride, a CNR (carrier-to-noise ratio) of 59 dB was achieved with a reading laser ( lambda =820 nm) power of 1 mW for a 2-MHz carrier at 10 m/s, and 64 dB with 3-mW read power for a 2.5-MHz carrier at 20 m/s. It is concluded that these Co/Pt multilayers are very promising as magnetooptical recording materials.< >