Effect of the preparation method on the structural and magnetic properties of the Fe₂Nb alloy

Abstract

In this paper we carried out the structural and magnetic study of the Fe 2 Nb stoichiometric alloy by means of x-rays diffraction and Mössbauer spectrometry. The samples were obtained by two different techniques, arcmelting and mechanical alloying, and then they were thermally treated. The structural properties of the alloy depend on the method of preparation: by the melting method it was possible to obtain the hcp-Fe 2 Nb ordered structure; while by mechanical alloying besides of the hcp structure also were formed the fcc-NbO and bcc-FeNb structures. After heat treatment of the melted alloy, this was submitted to mechanical alloying during 16 and 32 hours. Mechanical alloying allows the formation of bcc-FeNb grains which behave as superparamagnetic due to their small size and they are surrounded by hcp grains. Before heat treatment of the alloy obtained by mechanical alloying it was also found the existence of superparamagnetic bcc grains and the heat treatment increases the size of these bcc grains and the superparamagnetic-ferromagnetic transition is induced.

Mössbauer and X-ray Studies of Radiation-Induced Processes in Nb–Zr Alloys Implanted with 57Fe Ions

“…Moreover, a situation is possible when the depleted zone will be replenished with atoms predominantly of the same type. Fe combines with the matrix element (Nb), forming the Fe 2 Nb intermetallic compound, the Mössbauer parameters of which are similar to those of Doublet 1 and the intermetallic compound obtained by mechanical alloying [ 42 , 43 ]. The zirconium atoms return to their primary state, forming the Nb(Zr) solid solution.…”

Effect of Process Control Agents on Fe-15at.%Nb powder during Mechanical Alloying

“…Studying Fe-Nb binary system alloys via the MA process is important because it can provide alternative processes, like viable results for better understanding the system phase equilibrium, and for many alloy families based on Fe-Nb 8,9 . Some works have detailed this [10][11][12][13][14][15][16][17][18][19] . Most studies on Fe-Nb systems 10,12,13,[15][16][17][18] deal with systemically studying phase amorphization modes via the MA process, using milling times varying from 30 minutes to 70 hours.…”

“…Some works have detailed this [10][11][12][13][14][15][16][17][18][19] . Most studies on Fe-Nb systems 10,12,13,[15][16][17][18] deal with systemically studying phase amorphization modes via the MA process, using milling times varying from 30 minutes to 70 hours. Povstugar et al 13 , in addition to using MA, developed a heat treatment at 700 °C.…”

“…However, MA and heat treatment times were not specified for any phase that had been obtained. Vélez et al [15][16][17] published three works related to obtaining Fe-Nb alloys via MA, based on magnetic property studies that used two heat treatments seeking LAVES (Fe 2 Nb) phase formation. Roy et al 14 , analyzed the magnetic behavior of the LAVES amorphous phase prepared via MA.…”