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R. Grössinger:
"SMALL-ANGLE NEUTRON SCATTERING MEASURMENTS OF NANOCRYSTALLINE MAGNETIC MATERIALS";
Poster: SMM16 Conference: published in conference book, Düsseldorf, Deutschland; 09.09.2003 - 12.09.2003.

Abstract. Nanocrystalline soft-magnetic ribbons of the standard composition Fe73.5Nb3Cu1Si13.5B9 (so-called ?Finemet?) were investigated by small-angle neutron scattering (SANS) at the instrument D11 of the institute Laue-Langevin (ILL) Grenoble as a function of annealing temperature Ta. With increasing annealing temperature the number of nanocrystalline Fe-Si grains rises which are embedded in the amorphous matrix. Five ribbons annealed for 1 h at temperatures of 450 °C, 475 °C, 500 °C, 525 °C, and 550 °C were analysed by recording 2-dimensional SANS patterns at room temperature at a neutron wavelength of 0.6 nm for sample detector distances of 2, 8, and 28 m, corresponding to an accessible range of momentum transfers of about 0.025 < Q < 1.6 nm-1 and hence to structures in real space between 4 and 250 nm. Applying an external saturating magnetic field of 1.25 T allowed a separation of nuclear and magnetic scattering contributions. One specific sample was investigated at elevated temperatures of up to 470 °C, i.e. above the Curie temperature of the amorphous matrix, where the coupling between the nanocrystallites vanishes.