Title :
The residual amorphous phase in nanocrystalline soft magnetic FeSiCuNbB
Author :
Kuhrt, C. ; Herzer, G.
Author_Institution :
Corp. Res. & Dev., Siemens AG, Erlangen, Germany
fDate :
9/1/1996 12:00:00 AM
Abstract :
In order to synthesize separately the residual amorphous phase present in rapidly quenched nanocrystalline FeSiCuNbB ribbons, powders of nominal composition Fe92-xNb8Bx with x=19...45 as well as Fe63Nb9B28 and Fe 55Nb12B33 were mechanically alloyed for amorphization and annealed at 540°C for structural relaxation. The amorphous powder products show crystallization temperatures Tx1 and Tx2 increasing with B content from 600 to 750°C and 750 to 950°C respectively. The Curie temperature and also room-temperature saturation polarization show maximum values of about 140°C and 0.8 T at a B content of 25 at.%. Compared to that, the Curie temperature of the amorphous grain boundary phase of same composition in nanocrystalline FeSiCuNbB is by at least 100°C higher, presumably caused by exchange-field penetration from the adjacent α-FeSi nanocrystallites
Keywords :
Curie temperature; amorphisation; amorphous magnetic materials; annealing; boron alloys; copper alloys; ferromagnetic materials; iron alloys; mechanical alloying; nanostructured materials; niobium alloys; silicon alloys; soft magnetic materials; stress relaxation; 140 C; 540 C; 600 to 750 C; 750 to 950 C; Curie temperature; FeSiCuNbB; adjacent α-FeSi nanocrystallites; amorphization; amorphous grain boundary phase; amorphous powder products; annealed; crystallization temperatures; exchange-field penetration; mechanically alloyed; nanocrystalline soft magnetic FeSiCuNbB; residual amorphous phase; room-temperature saturation polarization; structural relaxation; Amorphous magnetic materials; Amorphous materials; Annealing; Iron alloys; Magnetic separation; Niobium alloys; Powders; Saturation magnetization; Soft magnetic materials; Temperature;
Journal_Title :
Magnetics, IEEE Transactions on
