Electroplated L1{sub 0} CoPt thick-film permanent magnets

The fabrication and magnetic characterization of 15-μm-thick electroplated L1{sub 0} CoPt hard magnets with good magnetic properties is reported in this paper. Experimental study of the dependence of the magnets' properties on annealing temperature reveals that an intrinsic coercivity H{sub ci} = ∼800 kA/m (10 kOe), squareness >0.8, and energy product of >150 kJ/m{sup 3} are obtained for photolithographically patterned structures (250 μm × 2 mm stripes; 15 μm thickness) electroplated on silicon substrates and annealed in hydrogen forming gas at 700 °C. Scanning electron microscopy is used to inspect the morphology of both the as-deposited and annealed magnetic layers, and X-ray Diffractometer analysis on the magnets annealed at 700 °C confirm a phase transformation to an ordered L1{sub 0} CoPt structure, with a minor phase of hcp Co. These thick films are intended for microsystems/MEMS applications.