First-order reversal curve analysis in the hysteretic behavior of boron-rich nanocomposite Nd–Fe–B ribbons

Structural and magnetic properties of melt-spun Nd4.5Fe72Co3Cr2Al1B17.5 ribbons were studied by means of differential scanning calorimetry, Mössbauer effect spectroscopy, X-ray diffraction and first-order reversal curve distributions. The presence of a solid solution (Fe, Co) in ribbons annealed at 685 °C for 10 min was detected from Mössbauer spectra. Correlations between the observed structural changes at higher annealing temperatures and modifications in the interaction fields of precipitated phases are discussed.