Glass formation and magnetic characterization of (Fe_(78)B_(14)Si_8)-Nb-Y alloys

摘要

In the present work, the glass formation of Fe_(78)B_(14)Si_8 alloy with small additions of Nb and Y has been investigated. Ribbons were prepared by planar-flow casting. Small ingots (up to 5 mm in diameter) were obtained by injection casting technique into a conical Cu mold. Thermal and structural properties were measured using differential scanning calorimetry (DSC) and X-ray diffraction (XRD), respectively. The microstructure has been observed by scanning electron microscopy (SEM). Quasi-static hysteresis loops have been measured using a vibrating sample magnetometer (VSM). Rapid solidification leads to a fully amorphous structure for all compositions. A partial amorphous structure has been obtained in samples prepared by copper mold casting, when adding Nb and Y. The role of Nb and Y addition on glass formation is discussed on the basis of melting behavior, analyzed by HT-DSC. Magnetic properties are correlated with the observed microstructures.