Magnetostriction and its susceptibility of Fe 3.2 Tb alloy thin film deposited on polyurethane rubber substrate with low deformation resistance by using direct current magnetron sputtering process were investigated. When both residual gas pressure before argon sputtering and sputtering pressure of argon gas (5 N) were less than 5.0×10 -4 Pa and 2.0×10 -1 Pa, respectively, the thickness of the Fe 3.2 Tb films deposited was about 2.96 mm. The giant magnetostriction was found in the Fe 3.2 Tb alloy film on polyurethane rubber sheet, rather than on other polymer sheets. Giant motion strain of Fe 3.2 Tb alloy film largely depended on deformation resistance of substrate. (Received December 25, 2007; Accepted March 18, 2008) Keywords: magnetostriction, susceptibility, mover film, terbium, iron, direct current magnetron sputtering 緒 言

Hydrogenation operates the bending motion of mover device, which is a platinum coated La Ni alloy film deposited on a polyimide sheet, has been successfully developed. Influence of the operating temperature on the motion strain has been evaluated. When the operating temperature is 373 K, the maximum value of bending strain (De) is 408 ppm, which is 1.4 times larger than that (300 ppm) of an unheated film operated at 323 K.

Influences of magnetostriction and magnetostrictive susceptibility of composite mover device of Fe Tb alloy thin film coated with Fe Pd alloy thin films on one side surface of silicon substrate prepared by DC magnetron sputtering process were investigated. The magnetic field induced the bending motion at 1000 kA/m. The magnetostriction and its susceptibility of the device film approximately corresponds to the average of values of Fe Tb and Fe Pd positive magnetostrictive thin films.