J. Phys. IV France 08 (1998) Pr2-39-Pr2-42
Magnetic and structural properties of nanocrystalline ultrathin Fe83Cu1Nb7B9 submitted to Joule heatingP. Tiberto1, F. Vinai1, P. Allia2, M. Baricco3, J.Y. Park4 and K.Y. Kim4
1 Istituto Elettrotecnico Nazionale Galileo Ferraris, 10125 Torino, Italy
2 Dipartimento di Fisica, Politecnico di Torino, 10129 Torino, Italy
3 Dipartimento di Chimica IFM, Universita di Torino, 10125 Torino, Italy
4 Division of Metals, Korea Institute of Sciences and Technology, Korea
Ultrathin (- 10 µm) ribbons of the amorphous alloy Fe83CU1Nb7B9 obtained by single roll melt spinning have been submitted to do Joule heating in vacuo in order to develop a nanocrystalline phase characterised by a very reduced grain size. The initial permeability of the nanocrystallized alloy was measured on open samples by means of a conventional fluxmetric technique with air-flux compensation. The interval of magnetising frequency was 100 Hz - 10 kHz. All samples were submitted to X-ray diffraction to evaluate the mean grain size, composition and strain level of the nanocrystalline phase. A substantial improvement in the magnetic permeability of Joule-heated nanocrystalline samples with respect to the conventionally annealed ones has been always found. Variations as high as 1000 times the as-quenched value have been observed for a wide range of electrical-current densities (4.107 ≤ j ≤ 6.107 A/m2).
© EDP Sciences 1998