本論文主要藉由同步輻射相關實驗研究三元複合錫化物Sr3Ir4Sn13中二維電荷密度波(two-dimensional charge density wave、2D-CDW)。實驗技術上包括X光散射(X-ray Scattering、XRS)、X光吸收近邊緣結構(X-ray absorption near-edge structures、XANES)、延伸X光吸收精細結構(Extended X-ray absorption fine structure、EXAFS)，探討高品質的 Sr3Ir4Sn13單晶樣品於相變溫度147K (T* ≈ 147 K) 時的電子與原子結構。
X光散射實驗中，在相變溫度下一系列衛星峰的發現，說明可能在沿著(1 1 0)平面上產生了2D-CDW。相變溫度下當沿著(1 1 0)平面，在EXAFS以及相衍生分析中，發現兩種不同的鍵結長度(Sn1(2)-Sn2)，證實了Sn原子的扭曲只發生在(1 1 0)平面上，與2D-CDW有強烈的相關性；而在XANES實驗中，Ir 5d軌域未佔據態的增加以及未佔據態幾乎沒有改變的Sn 5p軌域，說明了在電阻率的變化上，Ir 5d軌域未佔據態的改變相較於Sn 5p軌域扮演較重要的角色。因此在 Sr3Ir4Sn13樣品中，電子以及原子結構與2D-CDW有著密切的關係。

X-ray scattering (XRS), x-ray absorption near-edge structures (XANES) and extended x-ray absorption fine structure (EXAFS) spectroscopic techniques were used to study the electronic and atomic structures of high-quality Sr3Ir4Sn13 (SIS) single crystal both below and above transition temperature (T* ≈ 147 K).
     The evolution of a series of modulated satellite peaks below the transition temperature in XRS experiment indicated the formation of a possible two-dimensional charge density wave (2D-CDW) in the (110) plane. EXAFS phase derivative analysis supports the CDW-like formation by revealing the different bond distances [Sn1(2)-Sn2] below and above the T* in the (110) plane. XANES spectra at the Ir L3-edge and the Sn K-edge demonstrated an increase (decrease) in the unoccupied (occupied) density of Ir 5d-derived states and nearly constant density of Sn 5p-derived states at temperatures T < T*, in the (110) plane. These observations clearly suggest that the Ir 5d-derived states are closely related to the anomalous resistivity transition. Accordingly, a close relationship exists between local electronic and atomic structures and the 2D-CDW-like phase in the SIS single crystal.

目錄
致謝	i
圖表目錄	iii
第一章、緒論	1
1-1. 文獻回顧	1
1-2. 電荷密度波(Charge density wave)	3
第二章、實驗技術	6
2-1. 同步輻射	6
2-2. X光吸收光譜簡介	7
2-2-1. 吸收邊緣與E0值	9
2-2-2. X光吸收近邊緣結構(XANES)	10
2-2-3. 延伸X光吸收精細結構(EXAFS)	11
2-2-4. 實驗方法	16
2-2-5. 數據分析	20
第三章、實驗數據分析與討論	24
3-1. 樣品製備與基本量測	24
3-2. X光散射(XRS)之分析	29
3-3. 延伸X光吸收精細結構(Extended X-ray Absorption Fine Structure、EXAFS)之分析	33
3-4. X光吸收近邊緣結構(X-ray Absorption Near-Edge Structure、XANES)之分析	41
第四章、結論	56
參考文獻	57


圖表目錄
圖1-1(a) CDW發生前電荷間是趨向等距分佈	5
圖1-1(b) CDW發生後電荷間能自行調制藉由不等距分佈來降低系統總能	5
圖2-1光子能量與同吸收截面關係圖	8
圖2-2 XANES與EXAFS分界圖	13
圖2-3光電子平均自由路徑與能量關係圖	13
圖2-4單一散射與多重散射之圖像	14
圖2-5射出電子受鄰近原子的背向散射，而產生干涉現象	15
圖2-6 X光吸收光譜實驗示意圖	17
圖2-7三種光譜量測方法	19
圖2-8 X光吸收光譜之數據分析流程	20
圖3-1 SIS樣品(2 2 0)繞射峰	26
圖3-2 SIS樣品(1 1 0)平面之(a)變溫電阻率量測圖	27
(b)two theta long scan	27
圖3-3 (a)SIS樣品於I phase時的結構	28
(b)同步輻射光源電場偏振平行於(1 1 0)平面	28
(c)同步輻射光源電場偏振垂直於(1 1 0)平面	28
圖3-4不同溫度下針對衛星峰(3.5 4.5 0)所做量測結果	31
圖3-5衛星峰(3.5 4.5 0)積分強度以及半高寬對溫度作圖	32
圖3-6電場平行(1 1 0)平面變溫Sn K –edge EXAFS圖譜	35
圖3-7電場垂直(1 1 0)平面變溫Sn K –edge EXAFS圖譜	36
圖3-8電場平行(1 1 0)平面phase derivative analysis	39
圖3-9電場垂直(1 1 0)平面phase derivative analysis	40
圖3-10 (a)電場平行(1 1 0)平面Ir L3-edge變溫XANES圖譜	43
圖3-10 (b)電場垂直(1 1 0)平面Ir L3-edge變溫XANES圖譜	44
圖3-11電場平行及垂直(1 1 0)平面扣除背景值後積分強度對溫度作圖	45
圖3-12 (a)電場平行(1 1 0)平面Sn K-edge變溫XANES圖譜	47
圖3-12 (b)電場垂直(1 1 0)平面Sn K-edge變溫XANES圖譜	48
圖3-13 (a)高溫與低溫下平行(1 1 0)平面ARPES圖譜	52
圖3-13 (b)高溫與低溫下垂直(1 1 0)平面ARPES圖譜	53
圖3-14 (a)不同溫度下平行(1 1 0)平面費米面附近ARPES圖譜及一階微分結果	54
圖3-14 (b)不同溫度下垂直(1 1 0)平面費米面附近ARPES圖譜及一階微分結果	55

[1]Ritschel, T. et al. Orbital textures and charge density waves in transition metal dichalcogenides. Nature Phys. 11, 328 (2015).
[2]Yang, J. J. et al. Charge-orbital density wave and superconductivity in the strong spin-orbit coupled IrTe2:Pd. Phys. Rev. Lett. 108, 116402 (2012). 
[3]Borisenko, S. V. et al. Two energy gaps and Fermi-surface ‘‘arcs’’ in NbSe2. Phys. Rev. Lett. 102, 166402 (2009). 
[4]Ugeda, M. M. et al. Characterization of collective ground states in single-layer NbSe2. Nature Phys. 12, 92 (2016).
[5]Weber, F. et al. Extended phonon collapse and the origin of the charge-density wave in 2H-NbSe2. Phys. Rev. Lett. 107, 107403 (2011).
[6]Valla, T. et al. Quasiparticle spectra, charge-density waves, superconductivity, and electron-phonon coupling in 2H-NbSe2. Phys. Rev. Lett. 92, 086401 (2004).
[7]Kase, N., Hayamizu, H. & Akimitsu, J. Superconducting state in the ternary stannide superconductors R3T4Sn13 (R = La, Sr; T = Rh, Ir) with a quasiskutterudite structure. Phys. Rev. B 83, 184509 (2011).
[8]Tomy, C. V., Balakrishnan, G. & Pual, D. M. Observation of the peak effect in the superconductor Ca3Rh4Sn13. Phys. Rev. B 56, 8346 (1997).
[9]Goh, S. K. et al. Ambient pressure structural quantum critical point in the phase diagram of (CaxSr1−x)3Rh4Sn13. Phys. Rev. Lett. 114, 097002 (2015).
[10]Ślebarski, A. & Goraus, J. Electronic structure and crystallographic properties of skutterudite-related Ce3M4Sn13 and La3M4Sn13 (M = Co, Ru, and Rh). Phys. Rev. B 88, 155122 (2013).
[11]Thomas, E. L. et al. Crystal growth, transport, and magnetic properties of Ln3Co4Sn13(Ln = La, Ce) with a perovskite-like structure. J. Sol. Sta. Chem. 179, 1642 (2006).  
[12]Kase, N., Hayamizu, H., Inoue, K. & Akimitsu, J. Superconducting state in the ternary stannide R3Co4Sn13 (R = Ca, La). Physica C 471, 711 (2011).
[13]Liu, H. F., Kuo, C. N., Lue, C. S., Syu, K. Z. & Kuo, Y. K. Partially gapped Fermi surfaces in La3Co4Sn13 revealed by nuclear magnetic resonance. Phys. Rev. B 88, 115113 (2013).
[14]Israel, C. et al. Crystal structure and low-temperature physical properties of R3M4Sn13 (R = Ce, La; M = Ir, Co) intermetallics. Physica B 359, 251 (2005).
[15]Sato, H. et al. Magnetic and transport properties of RE3Ir4Sn13. Physica B 186, 630 (1993).
[16]Klintberg, L. E. et al. Pressure- and composition-induced structural quantum phase transition in the cubic superconductor (Sr, Ca)3Ir4Sn13. Phys. Rev. Lett. 109, 237008 (2012).
[17]Zhou, S. Y. et al. Nodeless superconductivity in Ca3Ir4Sn13: evidence from quasiparticle heat transport. Phys. Rev. B 86, 064504 (2012).
[18]Fang, A. F., Wang, X. B., Zheng, P. & Wang, N. L. Unconventional charge-density wave in Sr3Ir4Sn13 cubic superconductor revealed by optical spectroscopy study. Phys. Rev. B 90, 035115 (2014).
[19]Tompsett, D. A. Electronic structure and phonon instabilities in the vicinity of the quantum phase transition and superconductivity of (Sr,Ca)3Ir4Sn13. Phys. Rev. B 89, 075117 (2014).
[20]Kuo, C. N. et al. Characteristics of the phase transition near 147 K in Sr3Ir4Sn13. Phys. Rev. B 89, 094520 (2014).
[21]Mazzone, D. G. et al. Crystal structure and phonon softening in Ca3Ir4Sn13. Phys. Rev. B 92, 024101 (2015).
[22]Wang, L. M. et al.  Weakly-correlated nodeless superconductivity in single crystals of  Ca3Ir4Sn13 and  Sr3Ir4Sn13 revealed by critical fields, Hall  effect, and magnetoresistance measurements. New Journal of Physics 17, 033005 (2015).
[23]Kuo C. N. et al. Lattice distortion associated with Fermi-surface reconstruction in Sr3Rh4Sn13. Physical Review B 91, 165141 (2015).
[24]Luo C. W. et al. Dynamics of phonons in Sr3Ir4Sn13: An experimental study by ultrafast spectroscopy measurements. New Journal of Physics 18, 073045 (2016).
[25]Lue, C. S. et al. Comparative study of thermodynamic properties near the structural phase transitions in Sr3Rh4Sn13 and Sr3Ir4Sn13. Phys. Rev. B 93, 245119 (2016).
[26]Huang, C. H. et al. Electronic and atomic structures of quasi-one-dimensional K0.3MoO3. Appl. Phys. Lett. 86, 141905 (2005). 
[27]Du, C. H. et al. Direct measurement of spatial distortions of charge density waves in K0.3MoO3. Appl. Phys. Lett. 88, 241916 (2006). 
[28]Tsai, H. M. et al. Anisotropic electronic structure in quasi-one-dimensional K0.3MoO3: an angle-dependent x-ray absorption study. Appl. Phys. Lett. 91, 022109 (2007).  
[29]Kim, Y. J., Gu, G. D., Gog, T. & Casa, D. X-ray scattering study of charge density waves in La2−xBaxCuO4. Phys. Rev. B 77, 064520 (2008).
[30]Du, C. H. et al. The modulated structure and ferromagnetic insulating state in a nine-layer BaRuO3. J. Phys: Condens. Matt. 22, 036003 (2010). 
[31]Galli, F. et al. Charge-density-wave transitions in the local-moment magnet Er5Ir4Si10. Phys. Rev. Lett. 85, 158 (2000).
[32]R.E. Peierls, Quantum Theory of Solids (Clarendon, Oxford, 1955).
[33]Synchrotron Radiation Source, edited by Herman Winick (World scientific, 1997).
[34]'X-Ray Absorption: Principles, Applications, Techniques of EXAFS, SEXAFS and XANES', edited by D. C. Koningsberger and R. Prins (Wiley-interscience, 1988).
[35]“X-Ray Absorption : Principles, Application, Techniques of  EXAFS, SEXAFS, SEXAFS and XANES”, edited by D. C. Koningsberger, and R. Prins, Chem. Analysis Vol. 92 (Wiley 1988).
[36]D. E. Sayers, E. A. Stern, F. W. Lytle, Phys. Rev. Lett. 27, 1024 (1971).
[37]“NEXAFS Spectroscopy”, edited by Joachim Stöhr (Springer-Verlag 1991).
[38]E. A. Stern, M. Newville, B. Ravel, Y. Yaceby, and D. Haskel, Phys. B. 208&209, 117 (1995).
[39]“EXAFS and Near edge Structure”, edited by A. Bianconi, L. Incoccia and S. Stipcich (Springer-Verlay 1983).
[40]"EXAFS , Basic Principle and Data Analysis" , edited by Boon K. Teo (Springer-Verlag 1986）.
[41]“安全訓練手冊”,新竹同步輻射 (2001).
[42]C. S Hwang, F. Y. Lin, C. H. Lee, K. L. Yu, P. K. Tseng, J. T. Lin, H. C. Tseng, W. C. Su, J. R. Chen, T. L. Lin, W. F. Pong et al., Rev. Sci. Instrum. 69, 1230 (1998).
[43]Collins, M. F. Magnetic Critical Scattering (Oxford University Press, New York, 1989).
[44]Joseph, B. et al. Local structural displacements across the structural phase transition in IrTe2: order-disorder of dimers and role of Ir-Te correlations. Phys. Rev. B 88, 224109 (2013).
[45]Piamonteze, C. et al. Short-range charge order in RNiO3 perovskites (R=Pr, Nd, Eu, Y) probed by x-ray-absorption spectroscopy. Phys. Rev. B 71, 012104 (2005).
[46]Wang, B. Y. et al. Effect of geometry on the magnetic properties of CoFe2O4–PbTiO3 multiferroic composites. RSC Adv. 3, 7884 (2013).
[47]Clancy, J. P. et al. Spin-orbit coupling in iridium-based 5d compounds probed by x-ray absorption spectroscopy. Phys. Rev. B 86, 195131 (2012).
[48]Aluri, E. R. & Grosvenor, A. P. An x-ray absorption spectroscopic study of the effect of bond covalency on the electronic structure of Gd2Ti2-xSnxO7. Phys. Chem. Chem. Phys. 15, 10477 (2013).
[49]Mon, K. K., Ashcroft, N. W. & Chester, G. V. Core polarization and the structure of simple metals. Phys. Rev. B 19, 5103 (1979).
[50]Carter, G. C., Bennett, L. H. & Kahan, D. J. Metallic Shifts in NMR: A Review of Theory and Comprehensive Critical Data Compilation of Metallic Materials (Pergamon, Oxford, 1977).
[51]Rahn, D. J. et al. Gaps and kinks in the electronic structure of the superconductor 2H-NbSe2 from angle-resolved photoemission at 1 K. Phys. Rev. B 85, 224532 (2012).
[52]Tan, S. Y. et al. Photoemission study of the electronic structure and charge density waves of Na2Ti2Sb2O. Sci. Rep. 5, 9515 (2015).
[53]Gray, A. X. et al. Correlation-driven insulator-metal transition in near-ideal vanadium dioxide films. Phys. Rev. Lett. 116, 116403 (2016).
[54]Qazilbash, M. M. et al. Mott transition in VO2 revealed by infrared spectroscopy and nano-imaging. Science 318, 1750 (2007).
[55]Liu, M. K. et al. Anisotropic Electronic state via spontaneous phase separation in strained vanadium dioxide films. Phys. Rev. Lett. 111, 096602 (2013).