Microstructure and magnetic interactions in Pr–Fe–Co–Zr–Nb–B magnets

The microstructure and interactions between grains in Pr9Fe52Co13Zr1Nb4B21 magnets produced by short time annealing (at 983 K for 5 min) of rapidly solidified samples were investigated. The specimens were produced in the form of suction-cast 1 mm diameter rods, 1 mm thick plates and 3 mm outer diameter (o.d.) tubes. The X-ray diffraction analysis and Mössbauer spectroscopy shown presence of hard magnetic Pr2Fe11.2Co2.8B and paramagnetic Pr1+xFe4B4 crystalline phases diluted within the amorphous matrix in all samples. The microstructure was studied using TEM microscopy. Furthermore, rates of irreversible magnetization changes upon the change of external magnetic field H, were studied. In order to characterize interactions between grains of crystalline phases the δM curves were also constructed from recoil data.

► Magnets derived from novel bulk glass forming Pr9Fe52Co13Zr1Nb4B21 alloy by annealing at 983 K/5 min.
► Analysis of intergrain interactions by studying the δM plots.
► Studies of switching field distribution.
► Investigation of microstructure and phase constitution by TEM and Mössbauer spectroscopy.