Electroplated magnetic media with vertical anisotropy

Abstract

Alloys of CoMnP and CoNiMnP can be electroplated with a magnetic anistropy 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 anistotropy 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 interfacioal 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 of vertical recording.