Effect of processing parameters on the microstructure and soft magnetic properties of Fe88Zr7B4Cu1 alloy ribbons

Structure and soft magnetic properties of melt spun Fe88Zr7B4Cu1 alloy have been investigated using x-ray diffraction, differential scanning calorimetry, transmission electron microscopy and vibrating sample magnetometer. On decreasing the cooling rate the structure of as spun ribbon changes from completely amorphous to a cellular structure of bcc solid solution along with the amorphous phase at intercellular regions. Annealing leads to the precipitation of nanocrystalline bcc-Fe phase from both amorphous phase and already existing bcc solid solution. The saturation magnetization increases sharply for all samples on annealing at 500 0C due to the precipitation of nanocrystalline bcc phase and then remains almost constant at higher annealing temperatures. The coercivity decreases initially with annealing temperature, attains a minimum value and then increases at higher temperature