Zinc and Titanium Doped Tungsten Trioxide Ceramic Thermoelectric Performance

With method of double doping, WO3-based ceramics ZnO and TiO2 doped can be made into samples with different molar proportions. According to the X-ray diffraction pattern, analyze each dopant and the generation of second phase by Jade5, and with doping concentration changing substances of second phase will shift. The molar ratio of 0.5% and 1.0% doping concentrations produced as Zn0.3 WO3 the second phase, with the increasing doping amount, materials of the second phase shift, becoming coexistence of Zn0.3 WO3 and Zn0.06 WO3, the second phase is completely transformed into Zn0.06 WO3 at 5.0% (mole fraction). According to the SEM scanning electron microscope image, it can be found that the grain size decreases and then increases. Measure thermoelectric properties of doped ceramic material in the temperature range of 300 ~ 1 000 K. The experimental analysis shows, the conductivity decreases and then increases, conductivity of 2.0% (mole fraction) doped sample is the worst. Seebeck coefficient of the sample is negative, indicating WO3 doped n-type base ceramic thermoelectric material properties have not changed. The absolute value of the Seebeck coefficient is monotonically increasing, and as for the Seebeck coefficient of 2.0% and 5.0% (mole fraction) of the sample, there are difference between regions of low temperature and high temperature. When the doping concentration is 0.5% (mole fraction), the power factor is maximum, which is 0.052 μW / (m • K2).