Morphological structures and magnetic properties of sputtered thin film media

Morphological structures and magnetic properties of sputtered Co-Ni-Zr/Cr films are investigated in order to clarify the origin of an undesirable magnetic anisotropy induced by inline sputter deposition during disk transfer. The film deposition onto nontextured substrates at lower Ar pressure makes this anisotropy larger. Co-Ni-Zr/Cr films deposited at 1.3 Pa are observed to have bow-like columnar structures of Cr films and a preferential Cr<110> and Co<101> orientation inclined about 20 degrees from the direction normal to the film surface toward the transfer direction. As a result, the tendency of the magnetocrystalline anisotropy axis to face toward the transfer direction causes the magnetic anisotropy. This can be understood to be the origin of the undesirable anisotropy. On the other hand, the films deposited at 4.0 Pa have straight columnar structures of Cr films and a preferential Cr<111> orientation normal to the film surface. It is concluded that the morphological and crystallographic structures of Cr films strongly affect the magnetic properties of Co-alloy/Cr films.<
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