机械合金化法制备Co掺杂β-FeSi_2热电材料

Co-doped Thermoelectric β-FeSi_2 Prepared by Mechanical Alloying

采用机械合金化法—后续热处理法成功制备Co掺杂β-FeSi_2热电材料。用X射线衍射法分析球磨机转速和烧结工艺对混合粉末合金化进程的影响,测试样品的电学性能。结果表明:球磨时间为50h,球磨机转速为365 r/min时,球料质量比为15:1的球磨粉末在890℃烧结15 h(Ar气氛)后可完全生成β-FeSi_2,其中Fe_(0.97)Co_(0.03)Si_2具有最大功率因子,在600℃为74μW·m^(1).K^(-2)。而未掺杂FeSi_2的功率因子在600℃只为6.6μW.m^(-1).K^(-2)。

Co-doped thermoelectric β-FeSi2 were successfully fabricated by mechanical alloying followed by sintering process. The influences of ball-to-powder ratio and sintering conditions on alloying progress was studied by X-ray diffraction. The thermoelectric properties of the Co-doped FeSi2 were measured. Results showed that with the ball-to-powder ratio being 15：1, the mixed powder can be completely alloyed after sintering at 890℃ for 15 h in Ar atmosphere. Fe0.97Co0.03Si2 was found to have the maximum value of power factor of 74 uW·m^-1·K^-2 at 600℃. While that of FeSi2 is 6.6 uW·m^-1·K^-2 only.