Buntham Suwapitcha, Jiansirisomboon Sukanda, Watcharapasorn Anucha
J Nanosci Nanotechnol. 2015 Nov;15(11):9261-4. doi: 10.1166/jnn.2015.11417.
Bi0.5Na0.5TiO3-doped Na(x)CoO2 ceramics with varied doping concentration of 0, 0.01, 0.03, 0.05 and 0.07 mol fraction were prepared by conventional solid state reaction method. The firing condition used was 950 degrees C for 8 h. X-ray diffraction pattern results showed that all produced ceramics were single phase with a hexagonal structure. Due to the substitution of BNT inside Na(x)CoO2 lattice, there was a slight shift of X-ray diffraction pattern to the left which indicated the lattice expansion. The scanning electron micrographs of ceramics indicated that small amount of BNT addition could eliminate pore and improved densification. A small amount of undissolved BNT was also present in Na(x)CoO2 matrix and dispersed at grain boundaries causing a decrease in grain size of the ceramic. The electrical conductivity and Seebeck coefficient of ceramics showed that all samples possessed metallic conduction behavior. However, BNT addition caused a reduction of electrical conductivity, Seebeck coefficient and power factor of Na(x)CoO2 ceramics.
采用传统固相反应法制备了掺杂浓度分别为0、0.01、0.03、0.05和0.07摩尔分数的Bi0.5Na0.5TiO3掺杂Na(x)CoO2陶瓷。所用的烧结条件为950℃保温8小时。X射线衍射图谱结果表明，所有制备的陶瓷均为具有六方结构的单相。由于BNT在Na(x)CoO2晶格中的取代，X射线衍射图谱向左有轻微偏移，这表明晶格膨胀。陶瓷的扫描电子显微镜照片表明，少量BNT的加入可以消除气孔并提高致密化程度。在Na(x)CoO2基体中也存在少量未溶解的BNT，并分散在晶界处，导致陶瓷晶粒尺寸减小。陶瓷的电导率和塞贝克系数表明，所有样品都具有金属导电行为。然而，BNT的加入导致Na(x)CoO2陶瓷的电导率、塞贝克系数和功率因数降低。
