- 學位論文
矽與鍺共振多光繞射之相位研究
Resonant multi-wave x-ray diffraction study of phase problem on silicon and germanium
摘要
本論文使用共振多光繞射方法研究繞射光在晶體內之動力效應。利用多束繞射光在晶體內的同調干涉，由干涉過程把相位訊息帶出來，使其顯露在繞射圖譜上。不同能量之入射光，多光繞射結構因子乘積之不變相位與原子散射因子之異常色散修正有關。當入射x光能量接近繞射系統中的成分原子之吸收邊時，繞射的振幅與相位二者對能量之改變是非常靈敏變化。因此，在共振與非共振能量上，測量晶體內繞射光之同調干涉之結果得其相位資訊，了解相位資訊與異常色散之關聯性，與其繞射物理特性。共振能量附近，選擇禁制反射為一階繞射，有效降低色散修正實部之貢獻，同時考量結構因子在共振能量上具張量特性，藉此獲得更多的相位資訊。二階以上之繞射光則挑選較高階之反射面，降低靜力項於複繞射峰型之貢獻，定量的估計相位資訊。
並列摘要
This thesis reported that the multi-wave x-ray diffraction technology was employed in studying the dynamical effects of these diffracted beams in the crystals. These diffracted beams within the crystals produced the coherent interference. Phase information was extracted during the interference process and exhibited it on the diffraction pattern. The invariant phase of the structure factor of the multi-wave diffraction depended on the anomalous dispersion correction of the atomic scattering factor which changed with the different photon energy. Both of the amplitude and phase of the diffracted beams were very sensitive to shift with energy, when the incident x-rays were tuned to an energy close to the absorption K-edge for one of the constituent atoms of the diffraction system. Therefore, measuring the coherent interference of the diffracted beam in the crystal obtained the phase information at resonant and non-resonant conditions to understand the correlation between the phase information and the anomalous dispersion correction which were related to the properties of diffraction physics. Choosing the forbidden reflection as the primary reflection decreases the contribution of the real part of the anomalous dispersion correction and considering the tensor form properties of the structure factor near the resonant energy to receive more phase information. The high-order hkl reflections are chosen as the secondary reflection to reduce the kinematical effect in the multi-wave line-profile to estimate the phase information quantitatively.