In order to study the low temperature process to fabricate (001) oriented FePt granular structure, FePt-Ag and FePt-MgO films were fabricated by the repetition process of deposition of Fe40Pt40Ag20 (0.83 nm) or Fe40Pt40(MgO)20 (0.83 nm) alloy layer and subsequent annealing at Ta = 200˚C-400˚C. The FePt-Ag film showed (001) oriented structure together with rather high ordering parameter of 0.5 even at a low process temperature of 250 ˚C. The ordering parameter of FePt-Ag was found to be much higher than that of FePt-MgO. The FePt-Ag prepared by the repetition process at 250 ˚C had well isolated grain structure with diameters of several nm to several tens nm, and showed a large uniaxial anisotropy of 1.0 x 10 7 erg/cc. The application of the repetition process and Ag addition into FePt was found to be quite effective to fabricate well isolated L10 ordered FePt granular structure at a low process temperature.

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IKAROS, a solar sail spacecraft launched in 2010, demonstrated that thin-film solar cells can generate electricity. During this demonstration, it was found that the cells became curved, which destabilized the attitude of the spacecraft. Therefore, this study focused on a sputtering deposition technique that generates internal stress during the formation of thin films. The objective of this study was to control the curvature of a multilayer film by sputtering with a pattern. The effect of sputtering on the thin film was analyzed through experiments and simulations, and it was clarified that the cause of shape non-reproducibility is sputtering-induced stress.