Electrodeposited Co-Pt permanent micromagnet arrays on Cu[111]-Si[110] substrates

Co-Pt cylindrical micromagnets with 2-μm diameter have been successfully fabricated by electroplating through resist masks onto Cu[111] seed layers. The influence of the applied current density and cylinder height on the magnetic properties have been investigated. Both coercivity and retentivity increase with increasing aspect ratio, due to the combined effect of the decreasing demagnetizing field and the increasing perpendicular crystalline anisotropy of Co-Pt, which grows preferentially with HCP(0001) orientation. Values as high as 4.3 kOe for the coercivity and 6.9 kG for retentivity have been observed. Large energy products up to 5.38 MGOe (42.83 kJ/m³) were attained, rendering these structures potential candidates for hard magnetic components in microelectromechanical systems.