A plated magnetic thin film of high saturation magnetization and low coercivity having the general form Co100-a-bFeaMb, where M can be Mo, Cr, W, Ni or Rh, which is suitable for use in magnetic recording heads that write on narrow trackwidth, high coercivity media. The plating method that produces the alloy includes four current application processes: direct current, pulsed current, pulse reversed current and conditioned pulse reversed current.