A Study on the Formation of Magnetic Refrigerant La(Fe,Si)13 Compounds by Spark Plasma Sintering
H. Tsuji, A. Saito, T. Kobayashi, S. Sakurada
Toshiba Corp., Kawasaki, Japan
Abstract
The phase formation of magnetic-refrigerant La(Fe,Si)13 compounds with a NaZn13-type structure has been investigated using an electron probe micro analyzer (EPMA) and X-ray diffraction (XRD). The structure of a sample synthesized by solid-state reaction of fine elemental powders using a spark plasma sintering (SPS) technique was compared with that synthesized by conventional methods including a melt and solidification process. The conventional methods, namely, arc-melting and melt spinning, easily caused segregation of the Fe-rich phase. On the other hand, the remarkable NaZn 13-type structure was observed in the SPS sample. These experimental results indicate that homogenous distribution of the elements and short-range atomic diffusion are important for forming the NaZn-type structure efficiently.
