ELECTROPLATED MAGNETIC MEDIA WITH VERTICAL ANISOTROPY

Alloys of CoMnP and CoNiMnP can be electroplated with a magnetic anisotropy normal to the substrate and a high coercivity in the perpendicular direction. The magnetic properties of the plated films are strongly influenced by the substrate on which they are deposited, since the substrate determines the thickness of the transition layer in which the perpendicular anisotropy is developed. The incorporation of Ni results in a greater degree of <00.2> preferred orientation of the hcp phase of Co and also increases the coercivity of the material, as evidenced by VSM and x-ray diffraction on Cu coupons. The alloy properties are otherwise relatively insensitive to plating conditions. On NiP substrates, which resemble the NiFe underlayer of disks, the interfacial transition layer appears to be thicker than on Cu. Double-layer media disks were fabricated using these alloys and were tested with a single-pole head for vertical recording. The D50 values and noise levels were comparable to those of sputtered media, but the plated media exhibited lower signal levels. Disks with CoNiMnP media were not as good as those with CoMnP, possibly because of a thicker interfacial transition region. © 1990, The Electrochemical Society, Inc. All rights reserved.