本實驗主要是以研究新穎氧化物熱電材料為主，氧化物熱電材料為新興的一個熱電材料體系，有使用壽命長、無汙染等優點。而LaNiO3、SrFeO3及YBa2Cu3O7在熱電性質方面較少為人研究。
本論文除了探討母體材料的熱電性質之外，亦探討摻雜元素對於電性以及Seebeck係數等熱電參數的影響。本研究以溶膠-凝膠法及固態反應法分別合成出鎳酸鑭、鐵酸鍶以及釔鋇銅氧粉末，經壓靶成錠後以X光繞射分析鑑定結構，以阿基米德法量測體密度及計算相對密度，以SEM觀察其表面形貌，以霍爾量測系統測量載子濃度及載子遷移率，最後以Seebeck係數量測系統、RT加熱爐及閃光法熱傳導儀量測熱電性質。在密度方面，母體材料均會隨著燒結溫度之提升而提升，相對密度除了鐵酸鍶的86%之外，在純相時皆可以達到92%以上。在晶粒大小方面，鎳酸鑭的晶粒大小可以達到奈米等級。
在熱電性質方面，鎳酸鑭的電阻率會摻雜鐠及釤而上升，但Seebeck係數最大可以提升到摻雜50%鐠時之-38 μV/K，未摻雜之鎳酸鑭最大的ZT值在973 K時為0.012，摻雜50%釤可以將ZT最大值提升至0.026；鐵酸鍶的電導率在鋁摻雜之後最大可從11.1提升至122 S/cm。純相鐵酸鍶Seebeck係數最大值為60.6 μV/K，ZT最大出現在摻雜15 %鋁摻雜時，在973 K時最大值可以達到0.1；釔鋇銅氧的室溫電導率在摻雜5%銀之後，最大可從原本43.7提升至148.6 S/cm，純相釔鋇銅氧Seebeck係數最大值為110 μV/K。ZT值最大為摻雜5%銀時，在973 K時為0.11。

The aim of this work was to search for new oxide thermoelectrics, which are the late comers in the family of thermoelectric materials. However, they show some advantages such as low environment hazard and good chemical stability at high working temperature. The oxides studied in this work were LaNiO3, SrFeO3 and YBa2Cu3O7 because they have yet been investigated thoroughly for such applications. In addition to the pure phase of the above oxides, doping with various elements was also carried out in order to achieve better thermoelectric properties.
The samples were prepared by the sol-gel and solid state reaction methods. The phase purity and structure, bulk density, morphology, and currier concentration were studied by X-ray diffraction, Archimedes method, scanning electron microscopy, and Hall-effect measurements, respectively. The thermoelectric properties were obtained using a homemade Seebeck coefficient measurement unit, a high temperature R-T measurement chamber, as well as a flashing thermal conductivity measurement system. It was found that the relative density increased greatly as the sintering temperature increased. Except SrFeO3 which showed a relative density of 86%, the other two oxides had the relative density over 92%. Also, sol-gel prepared LaNiO3 showed a smallest grain size, in the order of 10s nm. In terms of the electrical and thermoelectric properties, Pr or Sm doping both increased LaNiO3 resistivity, while the Seebeck coefficient was also increased and the maximum value reached -38 μV/K for the 50%-Pr doped samples. The best ZT at 973 K was 0.012 for the un-doped LaNiO3, whereas 50%-Sm doped LaNiO3 showed an improved ZT of 0.026. The conductivity of SrFeO3 were increased from 11.1 to 122 S/cm by 15% Al doping. Although un-doped SrFeO3 showed a maximum Seebeck coefficient of 60.6 μV/K, the maximum ZT was achieved with the 15% Al-doped SrFeO3, which was 0.10 at 973 K. The room-temperature conductivity of YBa2Cu3O7 rose from 43.7 to 148.6 S/cm after doing with 5% Ag. The maximum Seebeck coefficient of 110 μV/K was measured with the un-doped YBa2Cu3O7. However, 5%-Ag doped YBa2Cu3O7 was found to have the best ZT of 0.11 at 973 K.

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