Magnetostriction and thermal expansion of polymer-bonded Nd4Fe77.5B18.5 nano-composite

Magnetostriction and thermal expansion of polymer‐bonded Nd4Fe77.5B18.5 nano‐composites are measured using strain gauge method. The XRD patterns and SEM pictures of the sample are used for microstructural studies which indicate of three nanometer‐grains of α‐Fe, Fe3B and 2‐14‐1 phases embedded in an amorphous matrix. The overall behavior of the thermal expansion is similar to the 2‐14‐1 single phase alloy. The magnetostriction results show huge magnitudes in order of 10−4 in the presence of relatively weak external magnetic fields. Magnetostriction mainly originates from single (domain) particle interactions of Nd‐sublattice in Nd2Fe14B phase.