The current revolution in magnetic recording technology is leading to remarkable increase in areal density. Innovations such as MR heads and PRML channels have prompted this sudden upturn in the growth rate for areal density. Products at 1 Gbit/sq.in., packing an incredible 10 GBytes into a single 3.5" disk-drive, seem to be just around the corner. Central to this revolution is our improved understanding of the read/write process and the ability to apply powerful readback detection techniques. The fascinating and challenging properties of the recording channel at high densities and data-rates will be described.
Ultrathin Co/Pd multilayered films were prepared by rf magnetron sputtering and the effects of deposition conditions such as sputtering gas pressure and palladium underlayer thickness on the perpendicular magnetic characteristics of the multilayer were investigated. It was found that predominant mode of magnetic reversal changed from domain wall motion to magnetic moment rotation as sputtering gas pressure increased. Palladium underlayer also influenced the magnetization reversal features, and contribution of magnetic rotation to the magnetic reversal increased as palladium underlayer thickness increased. It turned out that there existed an optimum pressure for maximum perpendicular anisotropy energy, and the pressure was lower for the film with thinner cobalt layer.
Exchange-coupled NdTbFeCo/TbFeCo double layered structure is one of the promising candidates for magneto-optic recording media in short wavelengths. Kerr llipticity should be considered with Kerr rotation angle to evaluate Figure of Merit in short wavelength, due to phase difference. In this research, Carrier to Noise ratio is measured with phase compensator to eliminate the effect of the phase difference in the short wavelengths.
Artificially modulated magnetic Co/Pd multilayer is one of the promising materials for magneto-optic recording in short wavelength laser beam. But due to the fact that the Co/Pd multilayer is in a non-equilibrium state in terms of free energy and the marneto-optic recording is a kind of thermal recording which is conducted around Curie temperature (^TC), the assessment of stability in the Co/Pd multilayer is crucially interested in both structural and magnetic properties. As the parameter of the assessment of stability, changes in particle size and perpendicular magnetic anisotropy of the Co/Pd multilayers as the structural and magnetic properties, respectively are discussed below and above ^TC. The temperature dependence of the both properties in the Co/Pd multilayers shows a great deviation below and above ^TC. We attribute the deviation in the properties to the role of magnetic exchange energy below ^TC in the Co/Pd multilayers.