Large Kerr rotation angle and magnetic characteristics of Co-Cr/Al multilayers prepared by plasma-free sputtering

Multilayers of 50 approximately 1500 AA Co-Cr/7 AA Al for perpendicular magnetic (PM) and magnetooptical (MO) recording media were prepared by the facing targets sputtering (FTS) method. It has been confirmed that the FTS apparatus can deposit the multilayers without significant interdiffusion at the boundary on the plasma-free substrates. The reflectance R was as high as 70% in the wavelength range of 4000 approximately 10,000 AA. The Kerr rotation angle theta /sub K/ of 7 AA Al/1500 AA Co-Cr/7 AA Al triple layers was as large as 0.41 degrees . The coercivity H/sub C/ of the multilayers was as high as about 1000 Oe, enough for PM media, by post-annealing at a temperature as low as 150 degrees C without significant decrease of R and theta /sub K/. Consequently, the 150 AA Co-Cr/7 AA Al multilayers prepared by using the FTS apparatus may be very useful for both MO and PM recording media.<
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