CAJ | 학술논문

In this paper, SmCo6.9Hf0.1 as-cast alloys and ribbons with the addition of either graphite (C) or carbon nanotubes (CNTs) were prepared by arc melting and melt-spinning, respectively. The effects of adding carbon on the structure and magnetic properties SmCo6.9Hf0.1 were investigated by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), magnetic force microscopy (MFM) and vibrating sample magnetometer (VSM). It was found that the micro-structure and magnetic structure of SmCo6.9Hf0.1 ribbons were changed obviously due to the introduction of C or CNTs, although their crystal structure was characterized as the same Sm(Co,Hf)7 single phase, no matter carbon was added or not. As a result, the magnetic properties of carbon-contained ribbons were enhanced in a certain degree. This was considered to be related to the refined equiaxed grains, small domain size and the pinning effect of C or CNTs-rich regions. The magnetic properties of SmCo6.9Hf0.1(CNTs)0.05 rib-bons reached Hc=12.5 kOe, Mr=57.0 emu/g and Mr/M2 T=0.788.