Study of the Effect of Boron Concentration on Magnetic and Structural Properties of Nd_7.5Pr_2.5Fe_90-xB_xMelt-Spun Alloys

Abstract

The Mössbauer spectroscopy and X-ray diraction techniques have been used to investigate the eect of boron concentration on the structural and magnetic properties of as-quenched and heat-treated melt-spun alloys Nd7.5Pr2.5Fe90−xBx (x = 6, 8, 10) produced by melt-spinning technique. X-ray diraction and Mössbauer spectroscopy results indicate that as-prepared samples are completely amorphous in nature. The X-ray diraction patterns of samples heat-treated at 700• C are indexed as Fe3B, α-Fe, (NdPr)2Fe14B and Fe23B6 phases. The Mössbauer spectra of heat-treated samples are very complex and constituted a number of sextets and a quadrupole doublet. Two main phases are (NdPr)2Fe14B hard and t-Fe3B soft magnetic phases while α-Fe and Nd23Fe6 are detected as minor phases. The average internal magnetic eld decreases with the increase of boron content; more sharply in as-prepared and comparatively slowly in heat-treated samples. The X-ray diraction and Mössbauer spectroscopy results are in good agreement with each other.