Giant magneto and anisotropic resistance in an epitaxial (110) DyFe2/YFe2 multilayer film
Abstract Anisotropic and giant magneto-resistance (AMR and GMR) measurements for a molecular beam epitaxy grown (1 1 0) multilayer film [50 A-DyFe 2 /50 A-YFe 2 ]×40 at 100 K are reported. The film possesses a bending field B B ∼5 T and an irreversible switching field B IS ∼5 T. These features allow the study of both AMR, and GMR caused by the creation not only of longitudinal but also transverse magnetic exchange springs, in the magnetically soft YFe 2 layers. Finally, rotation experiments in applied fields show that like DyFe 2 films, there is a metastable state aligned along a [ 1 1 0] axis at 100 K.
This paper presents a synchronous reluctance machine design for high-speed high-power applications, such as the motor/alternator for a flywheel energy storage system. The rotor consists of alternating layers of ferromagnetic and nonmagnetic steel that are joined together by a process known as explosion bonding. Analytical expressions for the direct and quadrature inductances of the machine are presented, and are then used to optimize machine design. These expressions compare well with results obtained from finite element analysis. Structural and electrical analyses of a 60 kW, 48000 r.p.m. machine indicate that the design will be appropriate for flywheel systems. Current work involves construction and testing of the above design.