研究報告

學年 101
學期 2
出版(發表)日期 2013-03-01
作品名稱 應用氣液態環境下原位電化學和光電伏特法操控強關聯電子特性
作品名稱(其他語言) The Characterization of Strongly Correlated Electrons through In-Situ Electrochemical and Photovoltaic Modifications inside the Gas and Liquid Environments
著者 莊程豪
單位 淡江大學物理學系
描述 計畫編號:NSC102-2112-M032-001
 研究期間:201303~201407
 研究經費:1,557,000
委託單位 行政院國家科學委員會
摘要 The intriguing and versatile behaviors, such as metallic/insulating transition, multiferriocs, unconventional superconductivity, and heavy-fermion, are discovered over a large variety of transition metal (TM) or rare earth related materials. The localized d or f electrons coordinated with closely neighbor electrons and atoms demonstrate the correlated interaction in respect of the coupling effect between spin, charge, orbital, and lattice items. Although non one-electron models (i.e. many-body theory and mean-field theory) are able to describe some features in the strongly correlated electrons systems, it is still poorly discussed the complex composite system to have the site- and element-specific determination resolving the ground state of multiple structures. Recently, an accurate tool of resonant inelastic X-ray scattering (RIXS) exhibits the correlated-electron characterizations from nearest neighbor (charge-transfer), local splitting (d-d), spin exchange (magnon), and collective crystalline (phonon) excitations during the de-excitation dynamic process. It is a growing demand for the interface reaction of TM oxide in Li-ion battery and solar cell, but the limits of environment, real-time, and real-position are the problems now. The in-situ electrochemical modification in the TM oxide electrode, the charge/discharge process for Li-ion retraction/insertion behavior induces the change of unoccupied/occupied 3d electrons and layered lattice structure in Li-ion battery. In terms of CdSe sensitized Ti〇2 composite system, the laser-excited electron-hole formation, separation, and transfer results in the electron/hole injection into electronic configuration and the reorganized hybridization strength of 3d electrons, except the lattice change. The outcome of accumulated electrons on the surface is the preliminary derivation for the chemical catalysis reaction. With the help of photon-in/photon-out technique and environmental control, X-ray absorption spectroscopy and RIXS techniques describe the band structure and different correlated-electrons excitations corresponding to the ^v^^-induced de-excitation dynamic process. The point of conducting atomic force microscopy (AFM) is to provide the microscopic imaging capabilities of the topography and electric conduction features for the electrochemical and photocatalyical redox effect. Therefore, both modifications with the add-in control of gas and liquid environments exhibit two controllable matters: (1) intra-modification due to exchange field, crystal field, and spin-orbit interactions; (2) inter-modification due to charge-transfer of metal-ligand bound. In my proposal, the controllable variations of liquid/gas environment, electrochemical redox, laser energy excitation, photocatalysis, and active/passive reactant provide the fundamental science and technology in the detailed and unique discussion. 特別且多樣性的物理現象,如金屬與絕緣體相轉變、多鐵性、非常規超導體、 重費米子系統,大多被發現於過渡和稀土金屬系統。局域化d或f電子與鄰近電 子及原子形成強關聯交互作用,其不同耦合效應來自於自旋、電荷、軌道、晶格 參數。雖然非單電子模型(如多體理論或平均場理論)可以解釋某些強關聯系統的 特性,但針對特定化學位置與元素,量測多重結構之基帶分布仍缺乏討論。最近 高解析共振非彈性光散射能譜,經由去激發動態過程,可發現強關聯系統的一些 電子行為,例如電荷轉移(鄰近)、d-d (局部晶格場)、磁量子(自旋交換)、聲子(整 體晶格)激發子現象。 鋰電池及太陽能電池應用中,過渡金屬氧化物的表面反應一直受到關注,但 目前環境、及時、位置因素限制住研究發展。在鋰電池充放電過程中,電化學原 位調控過渡金屬電極,產生鋰離子的遠離和遷入行為,引起3d占據和非占據態 能階改變和層狀晶體結構改變。在CdSe敏化Ti02複合材料,雷射光激發電子電 洞產生、分離、遷移現象,電子電洞可注入原電子組態中,在不影響晶體結構下 可引起3d混合軌域重新分佈,並且累積表面電子為化學催化反應的起源。由於 光進光出的優點和環境控制的可能性,同步輻射技術中,光吸收和共振非彈性光 散射能譜可以描述能帶結構和入射光能量有關的去激發動態過程。另外,電化學 和光催化所引起的氧化還原反應,可以利用電性原子力顯微鏡,提供表面形貌和 電性影像特點。因此,前述改質法附加氣液體環境控制可以展現兩種可操控反應 ⑴交換場、晶格場、自旋軌道交互作用所引起內部改質⑵金屬與配位基中電荷 轉移所引起相互改質。在我的計畫中,可控制變因為氣液態環境、電化學氧化還 原、雷射能量激發、光催化反應、活化及惰性反應物,將提供基礎物理和技術更 為詳盡且獨特的討論。
關鍵字 強關聯電子系統; 能源材料; 環境原位控制; 共振非彈性光散射能譜; 電性原子力顯微鏡; strongly correl ated-el ectron system; energy materials; in-situ environmental control; resonant inelastic X-ray scattering; conducting atomic force microscopy
語言 zh_TW
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機構典藏連結 ( http://tkuir.lib.tku.edu.tw:8080/dspace/handle/987654321/101290 )

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