Microstructure and Magnetic Properties of Mo Containing Nanoperm-Type Alloys

Abstract

The influence of composition changes on the devitrification process, microstructure and magnetic properties of (Fe,Co)MoB(Cu) alloys was investigated. Amorphous and nanocrystalline samples were studied by differential scanning calorimetry, thermomagnetic gravimetry, X-ray diffraction, transmission electron microscopy and vibrating sample magnetometry and obtained results are correlated. Cu addition increases the thermal stability and the crystalline fraction of the nanocrystalline microstructure and improves the soft magnetic properties of the alloy. As B content increases the thermal stability of the nanocrystalline microstructure decreases and for the 20 at.% B alloy boride crystals are formed during the first crystallization stage. Saturation magnetization decreases and Curie temperature of the amorphous phase increases with B content. Co addition lowers the volume fraction of nanocrystals and as Co content increases in the alloy nanocrystals are enriched by Co, Curie temperature of the amorphous phase increases, linearly with Co content, and saturation magnetization and coercive field of nanocrystalline alloys increase as well.