Influence of Nb, Mo, and Ti as doping metals on structure and magnetic response in NdFeB based melt spun ribbons

In this work, it is shown a comparative analysis of magnetic measurements that has been done over rapidly quenched melt-spinning alloyed ribbons with the formula NdyFe(86−y−x)B14Mx (X = 2, 4; Y = 7,8; M = Nb, Mo, Ti). The magnetic properties such as coercivity, saturation magnetization and energy product (B.H)max are analyzed for ribbons annealed for 20 min at 953 K in each case. It is observed that the sample with the highest saturation isNd7Fe77B14Mo2 (∼1400 kA.m−1) while the sample Nd8Fe74B14Nb4 has the lowest saturation value (∼600 kA.m−1). The sample Nd7Fe75B14Ti4 exhibits the lowest value (∼400 kA.m−1) while the Nd8Fe74B14Ti4 exhibits the highest value (∼700 kA.m−1) and the maximum (B.H)max value ∼110 kJ.m−3. The use of different experimental techniques, such as X-ray diffraction, Mössbauer spectroscopy, X-ray photoelectron spectroscopy, helped us to comprehend how M doping has influenced in a broad set of physical and chemical properties (e.g. crystalline phases, grain boundary doping enrichment, etc.) and how they correlate with the various observed magnetic features for these ribbons.