Fe thin films were deposited directly and via Ag underlayer on glass and MgO(100) substrates by MBE. Polycrystal Fe films grew on the glass substrate while single crystal films grew on the MgO(100) substrate. Fe film growth followed the Volmer-Weber mode for both cases. The Fe film structure was influenced by the surface roughness of Ag underlayer at the early stage of film growth. The relationships between the Fe thin film morphology and the magnetic properties are discussed.

A new magnetostrictive thin-film cantilever actuator and a new thin-film walking mechanism were developed. The actuators were made of magnetostrictive amorphous Tb-Fe and Sm-Fe thin films, deposited on the opposite sides of a polyimide film substrate. These actuators need not power supply cables because they were remotely driven by external magnetic fields. The static deflection of a 3-mm-long cantilever actuator was as large as 100 µm at 300 Oe field. Moreover the application of ac resonant frequency field of the same intensity yielded deflection of above 500 µm. The walking mechanism ran as fast as in the order of cm/s. The forward and backward running were possible depending on the frequency of applied magnetic field. Such unique characteristics suggest that magnetostrictive thin-film actuators are useful in MEMS applications.

The magnetic properties and the structure of electroless-deposited NiFeB films were investigated in comparison with those of electrodeposited NiFe films. The electroless-deposited NiFeB film with 27at% Fe content had the lowest coercivity, H, as low as 0.5 Oe with a saturation magnetic flux density, Bs, of 1.0 T. The saturation magnetostriction, λ, and the uniaxial magnetic anisotropy, Hk, were 5.010-6 and 10 Oe, respectively, which were larger than those of the conventional, electrodeposited permalloy film. The permeability of as-deposited Ni70Fe27B3 film was 1000 at 1 MHz. In order to improve the permeability, the film was heated at 200 in a magnetic field applied in the hard-axis direction to decrease the Hk value, and the permeability became 2000 at 1 MHz. The crystal structure and grain size of NiFeB and NiFe films were investigated by XRD, THEED and TEM. Both films with low Hc had an fcc structure; the grain size of the NiFeB film was smaller than 10 nm, while that of the NiFe film was larger, approximately 20 nm. The results suggested that the electroless-deposited NiFeB film had a larger magnetic anisotropy than the electrodeposited NiFe film. Moreover, the films with Hc less than 10 Oe ded not show clear difference between their TEM bright images and THEED patterns.