PREPARATION AND APPLICATIONS OF MAGNETOSTRICTIVE THIN-FILMS

Amorphous magnetostrictive films of the binary compound Sm xFe1-x as well as of the ternary compound (Tb yDy1-y)xFe1-x were prepared by rf or dc magnetron sputtering using either a multitarget arrangement with pure element targets or cast composite-type targets. The magnetostrictive properties of (Tb0.3Dy0.7)0.4Fe0.6 and Sm 0.4Fe0.6 films were investigated in relation to their preparation conditions. Depending upon these conditions (especially upon the deposition rate, the bias voltage, and the Ar sputtering pressure) amorphous films with a giant magnetostriction of about 250 ppm (-220 ppm) at 0.1 T and 400 ppm (-300 ppm) at 0.5 T for the TbDyFe (SmFe) and an in-plane magnetic easy axis could be prepared. In view of applications in microsystem technologies (e.g., pumps, valves, positioning elements) these films have been tested in a simple cantilever arrangement and the predicted deflection of a magnetostrictive actuated membrane has been calculated.