電荷密度波(CDW)常出現於低維度材料，即具有異向性一維的線性鏈或二維的平面的材料，如K0.3MoO3、NbSe3、TaS2、 K2Pt(CN)4Br0.332H2O等皆屬於這類的材料；在眾多電荷密度波材料中，二維層狀結構的TiSe2已受到長時間的關注，據文獻記載其電荷密度波會出現於(H±0.5 K±0.5 L±0.5)的位置並為對掌形電荷有序。
在經過退火過後， TiSe2受溫度影響Se元素會有些許消散使晶格排列改變，如此一來可能會造成相變溫度的轉變，本論文利用電子微探分析(Electron Probe Microanalyzer)確定Se含量，並藉由電性和磁性量測來估計其相變溫度，並藉由X-ray的散射來確認實際TiSe2的電荷密度波相變溫度，如此能了解不同的退火溫度樣品的品質會出現差異，且探討Se含量和退火溫度對相變溫度造成的影響 。

The modulated structure due to the formation of charge density wave (CDW) usually exists in low-dimensional materals, such as K0.3MoO3, NbSe3, TaS2, K2Pt(CN)4Br0.332H2O　and so on. The study of the charge modulations are mostly relied on the use of electron beams, x-rays, and neutrons. Among them, x-rays have the merits of high-spatial resolution and sensitive to charges over other two probes. In this study, we use the high-resolution x-rays to investigate the CDW modulation in a layered compound TiSe2 under different annealing temperatures.
Measurements on a series of crystals of TiSe2 being annealed at different temperatures show the different conductivity behavior, which were observed to relate to the Se contents by the use of Electron Probe X-Ray Microanalyzer.Using high-resolution x-ray scattering, many satellite reflections caused by the CDW were located at positions (H± 0.5 K± 0.5 L± 0.5) at low temperatures, and the transition temperature of CDW was also observed to depend on annealing temperatures.

目 錄
第一章 緒 論.............................................................................1
第二章 理 論.............................................................................2
2-1 同步輻射......................................................................................2
2-2 布拉格繞射 (Bragg's Law).........................................................5
2-3 晶體結構......................................................................................8
2-4 電子微探分析 (Electron Probe Microanalysis, EPMA)...........13
2-5 電荷密度波材料 (Charge Density Wave Materials)................15
2-5.1 層狀材料 (Layered Materials)........................................15
2-5.2 電荷密度波 (Charge Density Wave)..............................18
2-5.3 自由電子費米氣體 (Free Electron Fermi Gas)..............21
2-5.4 激子凝聚態 (Exciton Condensate Phase).......................27
第三章 實驗方法.....................................................................31
3-1實驗設施.....................................................................................31
3-1.1 光束線BL07A................................................................31
3-1.2 實驗站設置......................................................................33
3-1.3 低溫系統..........................................................................36 
3-2 實驗方法....................................................................................39
3-2.1 光源校準..........................................................................39
3-2.2 數據量測..........................................................................43
第四章 實驗數據與討論.........................................................45
4-1	 實驗數據..................................................................................45
4-2	 SH0626-TiSe2...........................................................................48
	4-2.1  SH0626-TiSe2實驗數據.................................................48
	4-2.2  SH0626-TiSe2數據討論.................................................57
4-3	 SH1027-TiSe2...........................................................................59
	4-3.1  SH1027-TiSe2實驗數據.................................................59
	4-3.2  SH1027-TiSe2數據討論.................................................64
第五章 結 論...........................................................................65
參考文獻...................................................................................67
 
圖目錄
圖(2-1-1)	同步輻射光源波段介紹........................................................2
圖(2-1-2)	同步輻射加速器設施示意圖................................................3
圖(2-1-3)	插件磁鐵的發光機制............................................................4
圖(2-1-4)	插件磁鐵的光源孔徑大小....................................................4
圖(2-1-5)	插件磁鐵的光子能量和光亮度分布....................................4
圖(2-2-1)	布拉格繞射表示圖................................................................7
圖(2-2-2)	建設性干涉............................................................................7
圖(2-2-3)	破壞性干涉............................................................................7
圖(2-3-1)	單位晶胞................................................................................8
圖(2-3-2)	晶系結構..............................................................................10
圖(2-4-1) 	(a)電子探測微分析儀構造, (b)波譜儀分析機制..............13
圖(2-5-1)	1T-TiSe2及2H-TiSe2結構圖...............................................16
圖(2-5-2) 	TiSe2單層鍵結結構圖........................................................16
圖(2-5-3)	金屬電性質能帶示意圖......................................................18
圖(2-5-4)	二維週期性晶格扭曲..........................................................20
圖(2-5-5)	自由電子氣體的色散關係..................................................23
圖(2-5-6) 	T=0時，不同維度下的 χ(q )..............................................24
圖(2-5-7) 	正常狀態的一維氣體金屬..................................................26
圖(2-5-8)	Peierls預測的一維氣體金屬..............................................26
圖(2-5-9)	Tise2俯視C軸的布里淵區...................................................28
圖(2-5-10)	傳導帶L、價帶Γ和spanning vectors的關係......................28
圖(2-5-11)	擴張範圍的布里淵區..........................................................29
圖(2-5-12)	Exciton生成電荷密度波的機制.........................................29
圖(2-5-13)	(a)Excitonic Insulator, (b)Peierls insulator..........................30
圖(2-5-14)	Exciton condensate和Peierls distortion機制的對應圖......30
圖(3-1-1)	BL07A光束線八環繞射儀.................................................33
圖(3-1-2)	低溫恆溫器載具..................................................................37
圖(3-1-3)	低溫恆溫器..........................................................................37
圖(3-1-4)	溫控器..................................................................................37
圖(3-1-5)	氦氣壓縮機..........................................................................37   　    
圖(3-1-6)	渦輪真空幫浦......................................................................37
圖(3-1-7)	鈹窗......................................................................................38
圖(3-1-8)	架設低溫系統後的繞射儀..................................................38
圖(3-2-1)	針尖高低校準......................................................................40
圖(3-2-2)	針尖左右校準......................................................................40
圖(3-2-3)	針尖和φ環角向器..............................................................42
圖(3-2-4)	望遠鏡..................................................................................42
圖(3-2-5)	望遠鏡的水平......................................................................42
圖(3-2-6)	完成校正後的整體情況......................................................42
圖(4-1-1)	化學氣相傳輸法..................................................................45
圖(4-1-2)	TiSe2電荷轉換示意圖........................................................46
圖(4-1-3)	樣品TiSe2(a)SH0626 700℃,(b)SH1027 550℃-1,
(c)SH1027 550℃-2..............................................................47
圖(4-2-1)	SH0626退火後Se含量.......................................................48
圖(4-2-2)	TiSe2電性量測....................................................................49
圖(4-2-3)	電性量測相變溫度的預測..................................................50
圖(4-2-4)	霍爾效應量測......................................................................50
圖(4-2-5)	不同退火溫度下的磁性量測(a)650℃,(b)700℃,
(c)850℃,(d)950℃................................................................51
圖(4-2-6)	磁性量測的倒數分析..........................................................52 
圖(4-2-7)	TiSe2磁性量測相變溫度的預測........................................52
圖(4-2-8)	Bragg Peak(0 1 5)三個方向的量測(a)Ｈ方向,  (b)Ｋ方向,  (c)Ｌ方向.............................................................................53
圖(4-2-9)	QCDW 三個方向的溫度對積分強度變化...........................54
圖(4-2-10)	QCDW 三個方向的溫度對半高寬變化...............................55
圖(4-2-11)	Q(-0.5, 1, 5)L方向的溫度對積分強度變化.......................56
圖(4-2-12)	Q(-0.5, 1, 5)L方向的溫度對半高寬變化...........................56
圖(4-2-13)	電性量測與磁性量測的相變溫度預估比較......................57
圖(4-2-14)	QCDW(-0.5 -0.5 4.5)和Q(-0.5 1 5)的相變溫度比較............58
圖(4-3-1)	SH0626退火後Se含量.......................................................59
圖(4-3-2)	QCDW 三個方向的溫度對強度變化...................................60
圖(4-3-3)	QCDW 三個方向的溫度對半高寬變化...............................61
圖(4-3-4)	QCDW (0.5 0.5 4.5) L方向的溫度對積分強度變化............62
圖(4-3-5)	QCDW (0.5 0.5 4.5) L方向的半高寬變化............................62
圖(4-3-6)	QCDW (0.5 0.5 4.5) XRD的溫度對積分強度變化..............63
圖(4-3-7)	QCDW (0.5 0.5 4.5) XRD的溫度對半高寬變化..................63

 
表目錄

表(2-3-1)	晶系結構..............................................................................9
表(4-2-1)	SH0626退火後TiSe2成分變化..........................................48
表(4-2-2)	Bragg Peak(0 1 5)三個方向的半高寬整理........................54
表(4-3-1)	SH0626退火後TiSe2成分變化.........................................59

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