NiO與CuO之軟X光共振非彈性散射研究

Measurements of Resonant Inelastic Soft X-ray Scattering on NiO and CuO

賴嘉宏(Chia-Hung Lai)

指導教授 ： 黃迪靖

國立清華大學/理學院/物理學系/博士(2014年)

摘要

強關聯電子系統的電子結構與磁性特性在凝態物理領域裡扮演著相當重要的課題，而共振非彈性X光散射實驗技術是研究電子結構與磁特性相當重要的技術之一。在軟X光能量範圍裡面，共振非彈性X光散射實驗技術可測量系統裡電子與電子之間交互作用所產生的局部激發(local excitation) 和集體激發(collective excitation)的訊息，無法由於一般的X光吸收光譜(X-ray absorption spectroscopy)與光電子光譜技術(X-ray photoemission pectroscopy)所獲得的。然而共振非彈性X光散射的量測技術往往要求相當高的入射光子通量。為了提高該技術的量測效率，我們發展全新的概念應用在共振非彈性X光散射量測技術上面，並且在建造一條具有高量測效率以及高解析力的軟X光非彈性散射光束線。藉由能量補償原理(energy compensation principle)確實提高該條光束線的量測效率，此外該光束線採用可彎曲式光柵(bendable grating)來修正散焦像差(defocus aberration)和慧形像差(coma aberration)使得該系統具有高解析能力特性。入射光能量範圍從700 eV至933 eV時，該系統的整體能量解析力可以高達10,000。本論文呈現一條全新建造的“高效率、高解析力之共振軟X光非彈性散射光束線”的試車成果，以及探討3

關鍵字

共振非彈性X光散射 ； 軟X光

並列摘要

Resonant inelastic X-ray scattering (RIXS) is a powerful technique for studying electronic structure. In the soft X-ray regime, RIXS provides essential information about local and collective excitations which can't be obtained from other X-ray spectroscopic methods, such as X-ray absorption spectroscopy (XAS) and photoemission spectroscopy. However, a RIXS measurment requires high photon flux. In order to increase the efficiency of RIXS measurement, we developed a highly efficient beamline and spectrometer of inelastic soft X-ray scattering at high resolution. The design and construction of the beamline and spectrometer was based on the energy compensation principle of grating dispersion. We used two bendable gratings to achieve a good energy resolution by eliminating the defocus and comma aberrations. The total resolving power for incident photon energy covering from the Fe L3-edge to the Cu L3-edge was between 7500 and 10,000. The design of this monochromator-spectrometer system also greatly enhances the efficiency of measurement of inelastic soft X-rays scattering. In this dissertation, we present commissioning results of this new RIXS beamline and its capability of measuring momentum-resolved RIXS of NiO and CuO.

並列關鍵字

RIXS ； NiO ； CuO

參考文獻

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