本計畫擬運用Ｘ-光光譜實驗方法對兩類鈣基金屬氧化物熱電材料，包括 Ca3Co4O9+x 和CaMnO3 之電子結構進行有系統的研究。主要的實驗工作為同步輻射Ｘ- 光光譜，包括Ｘ-吸收光譜和Ｘ-放射光譜。前者可提供特定元素的空軌域相關訊息，後 者則可提供占據態的相關資訊。為了解材料中關鍵元素之價態對物理性質的影響，我們 將以適當的元素對樣品進行有系統的參雜，用以調控元素價數和晶體形變藉此改變其物 性。我們的目的是對熱電相關物理特性與電子結構的關聯性進行了解。 We propose to investigate the electronic properties of two series of Ca-based metal oxide thermoelectric materials, including Ca3Co4O9+x andCaMnO3. The major xperimental works including X-ray absorption spectroscopy and X-ray emission spectroscopy will be utilized. The former provides information of the unoccupied states of specified elements, while the later can reveal information of the filled states. In order to understand the effect of a specific element on the physical properties of the material, samples will be systematically doped with appropriate elements. Our purpose is to understand the correlations between the thermoelectrically related properties and the electronic structure.
