Effect of Al on the Structure and Magnetic Properties of Nanocrystalline FeSiBPCu Melt-Spun Ribbons

In this work, we have studied the effects of the addition of Al on the structure, thermal behavior and magnetic properties of rapidly solidified Fe-83.3(Si0.25B0.562P0.188)(16-x)Cu0.7Alx (x = 0, 0.5, 1 and 1.5) melt spun ribbons prepared by single roller melt-spinning process. All of the samples were studied using various techniques such as X-ray diffraction (XRD), differential scanning calorimetry, vibrating sample magnetometer and B-H loop tracer. The average crystallite sizes obtained for the Al-added samples were in the range of 10-18 nm confirmed by XRD results. Thermal analysis results revealed that by adding Al up to 1 at.%, the first crystallization peak shifted towards lower temperature and second peak to the higher temperature compared to the sample without Al. The highest maximum saturation magnetization (1.8 T) was obtained for the 0.5 at.% Al added alloy. Also the magnitude of coercivity was lowest for 1 at.% Al-added alloy. This was mainly related to the decrease of magnetostriction and magnetocrystalline anisotropy substitution of Al atoms for Si, P and Fe in the structure of bcc-Fe.