Last modified: 2018-07-19
Abstract
Effect of the Boron Content on the Amorphization Process and Magnetic Properties of the Mechanically Alloyed Fe92-xNb8Bx Powders
T. Chabi1, N. Bensebaa1, S. Alleg1, S. Azzaza1, J.J. Sunol2 and E. K. Hlil3
1 Laboratoire de Magnétisme et Spectroscopie des solides, Département de Physique, Faculté des Sciences, Université Badji Mokhtar B.P. 12, 23000 Annaba, Algérie.
2 Departament De Fisica, Universitat de Girona, Campus Montilivi, 17071 Girona, Spain.
3 Institut NEEL, CNRS, Université Grenoble Alpes, 25 Rue des Martyrs BP 166, 38042 Grenoble Cedex 9, France.
Abstract
The effect of the B content on the microstructural, structural and magnetic properties of partially amorphous Fe92-xNb8Bx (x = 5, 10, 15 and 20) alloys has been investigated by means of scanning electron microscopy, X-ray diffraction, high and low temperature extraction-type magnetometers. The XRD results reveal the formation of a nanocomposite structure where nanocrystalline bcc α-Fe and Fe2B phases are embedded into an amorphous matrix. The FeB boride is observed for higher boron content (x = 15 and 20), and the crystallite sizes are in range of 7-24nm. As the B content increases, the amorphous phases-relative proportion and coercivity increase, whereas the saturation magnetization decreases. An important magnetic hardening occurs by lowering the temperature from 400 to 5 K for x = 20% B. the variation of the Curie temperature can be attributed to the heterogeneity of the amorphous matrix.
Keywords: Nanocrystalline materials; Mechanical alloying; Fe-Nb-B alloys; X-ray diffraction; Magnetic properties.