Microstructure and recording properties of bicrystal disks with GaAs substrates

Bicrystal disks with CoCrTa magnetic layer and Cr underlayer were fabricated on {001} GaAs single crystalline wafers. It is found that the epitaxial orientation relationship of Cr onto GaAs is {001} Cr/spl par/{001} GaAs. Disks with coercivity up to 2600 Oe, accompanied by near unity coercive and remanent squarenesses, were obtained. Measured medium noise power is extremely low and remains unchanged as recording density increases up to 4000 fr/mm. The recording properties of the bicrystal media are compared with those of conventional longitudinal thin film media which have similar coercivities. >