Structure and magnetic properties of multilayer Co/CN granular films

The magnetic and structural properties of a series of granular Co/CN films prepared by annealing multilayers of Co and CN have been studied. The films contained both hcp and fcc phases, and grain sizes were in the range 18-27 nm. The coercivity varied with cobalt fraction and with bilayer thickness, and a maximum room temperature coercivity of 1230 Oe was obtained for 50% cobalt and 2.7 nm bilayer thickness. Measurements of the time and temperatu re dependence of the highest coercivity films suggest that their coercivity is due primarily to the hcp phase and to the grain size. All films had rel atively low values of magnetic viscosity (2%-3%/decade). (C) 2000 American Institute of Physics. [S0021-8979(00)37808-2].