Formation of Sm–Co nanoparticles in a W matrix using multilayered precursors

Sm–Co particles have been produced in a W matrix by annealing sputtered Sm–Co/W multilayers with layer thicknesses of 5–28 nm at temperatures of 600–850 °C. The Sm–Co particles had the intermetallic 1:7 and 2:17 structures with sizes below 10 nm and coercivities in the range of 2–10 kOe. A reduction of magnetization with prolonged annealing has been observed and attributed to alloying of Co with both W and Si by interdiffusion through the W layer.