Magnetic and Thermoelectric Properties of Fe-Ti-Sn Alloys

The magnetic and thermoelectric properties of Fe3-xTixSn (x = 0-1) alloys were investigated. The Fe3-xTixSn (x = 0.5-1) alloys consisted of the Fe2TiSn Heusler phase, while the Fe3-xTixSn (x = 0-0.25) alloys contained the Fe3Sn phase together with the FeSn2 and Fe phases. Although the Fe2TiSn specimen showed the low saturation magnetization, the Fe3Sn specimen exhibited the high saturation magnetization. It was found that the Curie temperature of the Fe2TiSn phase was around 350 K. Thermoelectric property measurements revealed that the Fe3Sn specimen was an n-type thermoelectric material, whereas the Fe2TiSn specimen was a p-type thermoelectric material. The highest power factor of 317 mu W/mK(2) was obtained in the Fe2TiSn specimen, but this value was smaller than that of the Fe2VAl Heusler compound. This was due to the fact that the Seebeck coefficient of the Fe2TiSn specimen was lower than the value expected from a first-principles study.