Ti掺杂的n型SiC基复合材料的热电性能

Thermoelectric properties of Ti doped n type SiC composites

为了合成高热电性能的 n型 Si C基材料 ,尝试用过渡塑性相工艺对 Si C基复合材料进行了 Ti掺杂的实验。当以纳米级 Si C为原料 ,并选择合适的保温时间及温度 ,室温时功率因子 f P 可达 1.5× 10 -5W.m.K-2 ,40 0℃时上升至1.5× 10 -4W.m.K-2 ,与聚碳硅烷浸渍法合成的样品相比 ,f P 提高约 10 0倍。X射线衍射谱及扫描电镜结果显示 ,纳米Si C原料与微米原料相比 ,更易于烧结 ,Ti掺杂入 Si C的浓度更高 ,因而 Seeback系数有显著提高。

N type SiC materials with good thermoelectric properties were synthesized by doping Ti into SiC based on composites using the transient plastic phase processing (TPPP) method. The SiC was inifially a nano powder and the holding temperature and time were casefully selected. The power factor f P reaches 1.5×10 -5 W·m·K -2 at room temperature and increases to 1.5×10 -4 W·m·K -2 at 400℃, which is about 100 times the power factor used in the polycarbosilane reacting sintering method. XRD and SEM images show that there are more Ti donors in the SiC when the SiC begins as a nano powder, which contributes to the significant enhancement of the Seeback coefficient.