MAGNETIC-PROPERTIES OF GIANT MAGNETOSTRICTIVE TBDYFE FILMS

The magnetic properties of (Tb0.27Dy0.73)xFe1-x films dependent on composition and microstructure are investigated in the range of 0.2 less-than-or-equal-to x less-than-or-equal-to 0.46. Both amorphous and partially crystalline films are prepared by dc sputtering. Composition is determined by wavelength dispersive X-ray, oxygen content, and depth profile by nuclear reaction analysis and Auger electron spectroscopy. All films show a giant magnetostriction up to lambda almost-equal-to 400 x 10(-6) at an applied field of 1 T. A compensation minimum of polarization at room temperature was found for x almost-equal-to 0.24. The amorphous films are characterized by an in-plane easy axis of polarization, combined with a large in-plane susceptibility for low applied magnetic fields. The coercivity of polarization and magnetostriction is below 10 mT, the Curie temperature about 400 K. In contrast, the partially crystalline films show a coercivity of about 180 mT, a low susceptibility parallel as well as perpendicular to the film plane, and a Curie temperature of about 600 K.