E. Quandt et K. Seemann, FABRICATION AND SIMULATION OF MAGNETOSTRICTIVE THIN-FILM ACTUATORS, Sensors and actuators. A, Physical, 50(1-2), 1995, pp. 105-109
Sputter-deposited magnetostrictive films present an interesting opport
unity to realize actuators in microsystems, as they offer features lik
e contactless high-frequency operation, simple actuator designs and a
cost-effective manufacturing technique. Amorphous magnetostrictive fil
ms of the binary compound SmFe as well as of the ternary compound TbDy
Fe have been prepared by d.c. magnetron sputtering using either a mult
itarget arrangement with pure element targets or cast composite-type t
argets. Depending upon the composition and the sputtering conditions,
particularly upon the bias voltage, amorphous films with a giant magne
tostriction of about 250 ppm (-220 ppm) at 0.1 T and 400 ppm (-300 ppm
) at 0.5 T for TbDyFe (SmFe) and an adjustable magnetic easy axis can
be prepared. In view of their applications in microsystem technologies
(e.g., pumps, valves, positioning elements), these films have been te
sted in cantilever arrangements. The design of the actuators, such as
the lateral patterning of the magnetostrictive films, has been modulat
ed by means of finite-element calculations. For double-clamped beams o
r clamped membranes, these calculations reveal that lateral patterning
of the magnetostrictive films is essential in order to obtain large d
eflections.