Abstract: A nano-crystalline soft magnetic alloy ribbon having a structure being occupied by nano-crystalline particles having an average particle size of 50 nm or less at least 50% of the alloy structure. A ceramic insulation coating is formed on its surface so that the coating becomes thicker at the both ends of the ribbon than at the center in the transverse direction of the ribbon and the thickness dx at the coating ends and the average thickness da of the coating determined by a mass measurement method are in the relations of 1.2 da.ltoreq.dx.ltoreq.5 da and dx.ltoreq.10 .mu.m. With a magnetic core using such a nano-crystalline soft magnetic alloy ribbon, magnetic components including saturable reactor, transformer, saturable transformer, acceleration cavity and surge absorbing elements such as surge block core in neutral beam injector can realize a higher performance. The invention also results in a higher reliability for the devices using such magnetic components.

Abstract: A magnetic encoder containing a magnetic drum having on its side surface a plurality of magnetic signal-generating means having different magnetic pole pitches, and a plurality of magnetoresistance elements each disposed opposite to each of the magnetic signal-generating means. The magneto resistance elements include a plurality of series-connected thin, ferromagnetic layer patterns having a magnetoresistance effect so that an output signal of each magnetoresistance element is in the form of a substantially sinusoidal curve. The magnetic pole pitch of one magnetic signal-generating means is 5 times or more the magnetic pole pitch of other magnetic signal-generating means, and the magnetoresistance element opposite to the magnetic signal-generating means having a larger magnetic pole pitch includes by 5 or more series-connected thin, ferromagnetic layer patterns within the range of one-fourth the larger magnetic pole pitch.