臺灣博碩士論文加值系統

本研究別以助熔長晶法，合成出具新穎結構化合物(1) Ba3.5Cu7.625+3δIn1.125-δSe9。化合物(1)以助熔長晶法，在高溫800⁰C下合成晶體，晶體的晶系及空間群為Orthorhombic Pnma，單位晶格的a、b、c軸長為a= 46.1700(12) Å, b= 4.26710(10) Å, c= 19.8125(5) Å。結構利用CuSe3、 MSe4 (M=Cu, In)，以共用Se相互連接形成3D立體結構骨架，沿b軸的結構孔道中填有Ba2+陽離子及以共用Se形式連結，沿b軸無限延伸的InSe4。化合物(1)因部分位置有Cu/In的錯排及混填的情形，造成分子式電荷沒有平衡，故以佔有率及價數平衡原則做分子式計算。
除了化合物(1)外，本研究另外以高溫長晶法，合成出一新穎結構化合物(2) Ba3Ag3In1Te6。將藥品置入事先鍍有碳膜的石英管中抽真空密封後，在高溫650⁰C下合成晶體，晶體的晶系及空間群為Orthorhombic Cmc21，單位晶格的a、b、c軸長為a= 4.5669(5) Å, b= 27.937(3) Å, c= 13.3819(13) Å。由MTe4 (M= Ag, In)以共用Te形式連結形成3D結構，結構孔道中填有Ba2+陽離子。

SUMMARY

Two new quaternary metal chalcogenides─Ba3.5Cu7.625+3δIn1.125-δSe9 (1) and Ba3Ag3In1Te6 (2), have been synthesized using KBr flux at 800 ⁰C, and using carbon-coating silica tubes at 650 ⁰C respectively.(1) crystallizes in in the Orthorhombic Pnma space group with a= 46.1700(12) Å, b= 4.26710(10) Å, c= 19.8125(5) Å, and (2) crystallizes in in the Orthorhombic Cmc21 space group with a= 4.5669(5) Å, b= 27.937(3) Å, c= 13.3819(13) Å. While the compound(1) shows a three-dimensional (3D) structure composed of CuSe4 tetrahedra, CuSe3 trigonal with the structural tunnel filled with Ba2+ and InSe4 tetrahedra along b-axis, the compound (2) also shows a three-dimensional (3D) structure composed of AgTe4 and InTe4 tetrahedra with the structural tunnel filled with Ba2+ along a-axis. There is complicated structure such as disorder of Cu/In and deficiency of Cu sites in compound (1) and heavey atoms like Ag and Te in compound (2), both situations would expect to decrease lattice thermal coductivity κl, and so the two new quaternary metal chalcogenides would be expected to exhibit high figure of merit (ZT) of thermoelectric materials(TE).

KWORDS: metal chalcogenides,

INTRODUCTION

There is so many effort to research in metal chalcogenides due to their potential in widespread applications, including Thermoelectric devices, rechargeable batteries, nonlinear optical materials and Transparent conducting oxide of solar cells. Copper-containing chalcogenides also exhibit many special physical properties in many past researches. The simple representive compound Cu2-xSe was reported and investigated not only in its structure but also physical properties because of its Cu deficiency and its charge unbalance situation. After so many researches in Cu2-xSe, Cu2Te and Ag2Te were reported to use as Thermoelectric materials in 1998 and 2005 respectively.
From 2001, there were a series of Ba-Cu-Te compounds were synthesized, including BaCu2Te2, A2BaCu8Te10(A=K, Rb, Cs), Ba3Cu14-xTe12, Ba6.76Cu2.42Te14, Ba2Cu4-xTe5 and Ba2Cu7-xTe6. All of them are usually show Cu clusters and Cu deficiency.
Base on the Ba-Cu-Te researches, here we represent two compounds, Ba3.5Cu7.625+3δIn1.125-δSe9 (1) and Ba3Ag3In1Te6 (2), which are the first members discovered in quaternary Ba/M/In/Q (M=Cu, Ag; Q=Se, Te) systems. Just like other Ba-Cu-Te systems, compound (1) also exhibit Cu clusters, Cu deficiency and structural holes. The compound (2) contains heavy atoms Ag and Te, and also structural holes. Both complicated structure in compound (1) and compound (2) contains heavy atom would expect to decrease lattice thermal coductivity κl and increase the figure of merit (ZT).

MATERIALS AND METHODS

Synthesis. The chemicals used in the reactions of compound (1) were barium (pieces, Aldrich, 99.9%), copper (40-80mesh, 99.9%), indium (shot, Aldrich, 99.9+%), selenium (pellets, Aldrich, 99.9%), potassium bromide (powder, 99.6%, J.T. Baker). Manipulation of barium were under dry N2 atmosphere in an OMNI-LAB glovebox.The reactants were loaded in fused silica tubes (diameter: 8 mm) and sealed under vacuum (〈10-4 Torr). Tubes were heated to 300 ⁰C within 5 hours from room temperature, hold in 300 ⁰C for 6 hours. Raised form 300 ⁰C to 800 ⁰C within 20 hours, stayed in 800 ⁰C for 96 hours, the reaction were then cooled to 300 ⁰C within 50 hours then turned off the power, and the products were naturally cooled to room temperature.

The chemicals used in the reactions of compound (2) were barium (pieces, Aldrich, 99.9%), silver (mesh, Aldrich, 99.9%), indium (shot, Aldrich, 99.9+%), tellurium (shot, Aldrich, 99.9%). Manipulation of barium were under dry N2 atmosphere in an OMNI-LAB glovebox.The reactants were loaded in fused silica tubes (diameter: 8 mm) and sealed under vacuum (〈10-4 Torr). The silica tubes would be coated a carbon film in advanced to prevent active glass attack of barium in high temperature reaction. Tubes were heated to 650 ⁰C (total weight of reactants under 1 g) or 800 ⁰C (total weight of reactants over 1 g) within 6 hours, stayed for 96 hours, and then cooled by the speed 10 ⁰C/hour to 300 ⁰C, and the products were naturally cooled to room temperature.

Physical Measurement. Electron Microscopy. Semiquantitative analyses of crystal were performed using a Hitachi SU-1500 scanning electron microscope equipped with a Horiba EMAX-ENERGY energy dispersive spectrometer (EDS). The data were acquired using an accelerating voltage of 10 kV. The EDS results analyzed by the EMAX Suite version 1.9 gave the average composition of Ba3.00(10)Ag2.88(11)In1.04(10)Te5.82(12) for (2). The compound (1) didn’t observe a consistent result in the EDS analysis because there were Cu/In disorder in crystal.

X-ray Crystallography. Single crystal s of compound (1) and (2) were selected for indexing and data collection on a Bruker APEXII CCD diffractometer, irradiating with graphite-monochromatized Mo Kα radiation (λ = 0.71073 Å). Data integrations and empirical absorption corrections were performed using the SAINT and SADABS functions, respectively, in the APEX2 package. The structures were solved and refined using the SHELXTL-97 package.
The measured powder patterns of compound (1) and (2) were collected using a Simadzu XRD-7000s X-ray diffractometer, which compared well with the patterns simulated from the results of single-crystal X-ray structural analyses.

RESULTS AND DISCUSSION

Compound (1) adopts a three-dimensional (3D) framework structure, assembled by CuSe4 tetrahedron and CuSe3 trigonal with Ba2+ cations and InSe4 distributed within the framework. The framework can be separated into four copper clusters with deficient Cu7 which is half occupied, Cu/In disorder in Cu8/In8, Cu16/In16, and mixed Cu4/In4, Cu12/In12 (Table1).
Compound (2) also adopts a three-dimensional (3D) framework structure, assembled by AgTe4 and InTe4 tetrahedron with Ba2+ cations distributed within the framework to charge balance. The pure phase of compound (2) was comfirm by Total Pattern Analysis Solutions (TOPAS)(Figure1).

Table1 Coordination and Occpancy of 4, 7, 8, 12, 16

Figure 1 Pure phase of compound (2)

CONCLUSION
Two new quaternary metal chalcogenides, compound (1) and compound (2), had been successfully synthesized with complicated structure in compound (1) and heavy atoms in compound (2). The investigation of the two compounds would continue to synthesize bulk materials so that can be use to make measurement such as Hole Effect, thermal conductivity, and the figure of merit (ZT).

摘要 II
Abstract IV
第一章 緒論 1
第二章 化合物(1)、(2)之合成與鑑定
4
2.1合成 4
2.2單晶X光繞射分析 6
2.3能量散佈光譜儀 8
2.4粉末X光繞射分析 9
2.5微差熱分析 11
2.6 垂直長晶法……...…………………………………..…… 11
第三章 結構描述與純相討論 12
3.1 單晶結構 12
3.1.1 化合物1結構描述 13
3.1.2 化合物2結構描述 21
3.2純相討論 25
3.2.1 化合物1純相討論 25
3.2.2 化合物2純相討論 35
第四章 結論 46
第五章 參考文獻 47
第六章 附錄 49

圖 1-1 BaCu2Te2及Ba3Cu14-xTe12結構圖。 3
圖 1-2 Ba3Cu14-xTe12隨溫度改變量測之席貝克係數及導電率。 3
圖 3-1 化合物1沿b軸看整體結構圖 15
圖 3-2 化合物1骨架基本單元以ORTEP方式呈現，分別以(1)(2)(3)(4)標示四個組成團簇；圖中熱擾動參數以60%計算。 16
圖 3-3 (a)和(b)分別為化合物1骨架基本單元中之區域(1)及(2)以ORTEP方式呈現；圖中熱擾動參數以60%計算。 17
圖 3-4 (a)和(b)分別為化合物1骨架基本單元中之區域(3)及(4)以ORTEP方式呈現；圖中熱擾動參數以60%計算。 19
圖 3-5 化合物2沿a軸方向整體結構圖，區域(1)為[Ag3Te8]，區域(2)為 [InTe4] 22
圖 3-6 圖中(a)、(b)為構成化合物2骨架基本單元由之區域(1)及(2)沿[111]方向觀看，以ORTEP方式呈現；圖中熱擾動參數以60%計算。 23
圖 3-7 化合物2沿c軸無限延伸[Ag3In1Te6]長鏈以ORTEP方式呈現；圖中熱擾動參數以60%計算。。 24
圖 3-8 化合物2經垂直b軸的c-glide或沿c軸的21screw axis對稱 24
圖 3-9 化合物1以粉末是X光繞射儀以2θ = 5~60 ⁰鑑定粉末晶相。黑色曲線為理論繞射圖，紅色曲線為實際測量圖。 26
圖 3-10 化合物1同步輻射測量(λ=0.6888 Å)，測量範圍2θ = 5~35⁰，黑色曲線為理論繞射圖，紅色曲線為實際測量圖。圓圈所示為5~10 ⁰出現的繞射峰。 26
圖 3-11 紅色曲線為化合物1以Ba：Cu：In：Se = 3.5：7.625：1.125：9比例，緩慢降溫下所得之X光繞射圖，黑色曲線則為單晶解得知理論圖，中間淺藍色及深藍色曲線為文獻中找到的BaCu2Se2及CuInSe2 X光繞射圖，兩圖繞射峰與紅色曲線實際測得的繞射峰重疊，推斷產物為兩三元物混合。 28
圖 3-12 紅色曲線為化合物1以焠火方式所得之X光繞射圖，與黑色理論曲線相比，多出的13 ⁰附近的繞射峰以藍色圓圈標示。 29
圖 3-13 化合物1之Cu比例由7.625(紅色曲線A)調降為7.6(淺藍色曲線B)及7.55(深藍色曲線C)時，與理論圖相比(黑色曲線) 13 ⁰附近的雜相繞射峰(藍色圓圈標示)並未消失。 29
圖 3-14 化合物1將Cu比例由7.625(紫色曲線A)調高為7.65(藍色曲線B)及7.7(紅色曲線C)與理論圖(黑色曲線)比較，圓圈所標示13 ⁰附近位置雜相繞射峰有消失趨勢。 30
圖 3-15 化合物1將Se比例由9(紫色曲線A)調降為8.9(紅色曲線B)、8.8(淺藍色曲線C)、8.75(深藍色曲線D)，曲線D晶相已完全不同。 32
圖 3-16 化合物1在400⁰C(藍色曲線)及300⁰C(紅色曲線)退火兩天與理論圖(黑色曲線)對照結果。 32
圖 3-17 化合物1在400⁰C(藍色曲線)及300⁰C(紅色曲線)退火一天與理論圖(黑色曲線)對照結果。 33
圖 3-18 化合物1經微差熱分析(DTA)重複兩次循環，皆在685⁰C處出現明顯的能量吸收峰，確定再結晶點為685⁰C。 34
圖 3-19合物2之粉末X光繞射圖；紅色曲線為化合物2實測繞射圖，黑色曲線為單晶數據所得理論繞射圖。 36
圖 3-20化合物2晶Topas軟體與晶體理論粉末繞射圖精算結果。....................................................................................37
圖 3-21 化合物2經微差熱分析後結果圖。紅色及藍色曲線分別為第一次及第二次循環；結果顯示化合物2熔點為595⁰C，再結晶點為610⁰C。 38
考慮Ag的高熔點及反應藥品的受熱均勻情形，調整反應溫度及石英管的口徑後，歸納出當反應總藥量在超過1 g時，增大石英管口徑並將反應溫度調高至850⁰C後可反應合成出純相目標產物。 39
圖 3-22 反應溫度650⁰C，總藥量提高至4 g之X光繞射圖比對；紅色曲線為實際產物繞射圖，黑色曲線為理論X光繞射圖。 39
圖 3-23 化合物2縮短反應時間所呈現之繞射圖結果，紅色曲線為2天焠火、藍色曲線為3天焠火、黑色曲線為理論繞射圖。 40
圖 3-24 化合物2晶退火1天之X光繞射圖；紅色曲線及藍色曲線分別為2天、3天焠火後再退火1天的結果。 41
圖 3-25 化合物2由塊狀(左圖)經數日時間轉變為粉狀(右圖) 44
圖 3-26 化合物2隨時間增長繞射峰強度明顯變弱；圖中黑色曲線為對照的理論繞射圖，紅色(A)為0週、藍色(B)1週、紫色(C)3週，咖啡色(D)為5週的繞射圖。 45
圖 3-27 化合物2產物追蹤至6週及8週之X光繞射圖；藍色曲線及紅色曲線分別為6周及8周後，黑色曲線為理論繞射圖。 45
圖 3-28化合物2以垂直長晶法總藥量4.5 g所得出產物結果。 43
圖 3-29合物2以垂直長晶法總藥量達9 g出現石英管壁破裂。 43

圖 1-1 BaCu2Te2及Ba3Cu14-xTe12結構圖。 3
表 3-1 化合物1和2部分單晶數據 12
表 3-2 化合物1中區域(1)鍵長資料 (Å) 18
表 3-3 化合物1區域(2)鍵長資料 (Å) 18
表 3-4 化合物1中區域(3)鍵長資料 (Å) 20
表 3-5 化合物1中區域(4)鍵長資料 (Å) 20
表 3-6 化合物2陽離子Bond Valance Sum 21
表 3-7 Ag-Te及In-Te鍵長資料 ( Å ) 23
表 3-8 化合物2 EDS分析結果比較 36
表 6-1 化合物1單晶繞射數據 49
表 6-2 化合物1原子位置和熱擾動參數 50
表 6-3 化合物1鍵長列表(Å) 52
表 6-4 化合物1的Bond Valence Sum 55
表 6-5 化合物1熱擾動參數 56
表 6-6 化合物2單晶繞射數據 58
表 6-7 化合物2原子位置和熱擾動參數 59
表 6-8 化合物2鍵長列表 60
表 6-9 化合物2的Bond Valence Sum 61
表 6-10 化合物2熱擾動參數 61

[1]DiSalvo, F. J. Science 1999, 285, 703-706
[2]Tritt, T. M. Science 1999, 283, 804.
[3]Mercoui G. Kanatzidis Chem. Mater. 2010, 22, 646-659
[4]Tarascon J. M., Armand M. Nature 2001, 414, 359-367
[5]Finlayson, N., Banyai, W. C., and Seaton, C. T. J. Opt. Soc. Am. 1989, 6B, 675-684
[6]Kim, Y., Seo, I. S., Martin, S. W., Baek, J., Halasyamani, P. S., Arumugam, N., and Steinfink, H. Chem. Mater. 2008, 20, 6048-6052
[7]Abrahams S. C.; Bernstein J. L., J. Chem. Phy. 1974, 61, 1140-1146
[8]Andreas Stadler Materials 2012, 5, 661-683
[9]Krishnapriyan A., Barton P. T., Miao M. and Seshadri R. J. Phys.: Condens. Matter 2014, 26, 155802
[10]Heyding R. D., Murry R. M. Can. J. Chem. 1976, 54, 841-848
[11]Oliveria M., McMullan R. K., Wuensch B. J. Solid State Ion.1988, 28-30, 1332-1337
[12]Ohtani, T. et al. J. Alloys Compounds1998, 279, 136-141
[13]Machado K. D., de Lima J. C., Grandi T. A., Campos C. E. M.,
Maurmann C. E., Gasperin A. A. M., Souza S. M. Pimenta, A. F. Acta Crystallogr., Sect. B 2004, 60, 282–286
[14]Liu H.L., Shi X., Xu F.F., Zhang L.L., Zhang W.Q., Chen L. D., Li Q., Uher C., Day T., Snyder G. J. Nature Mater.2012, 11, 422-425
[15]Sridhar K.,Chattopadhyay K. J. Alloys Compd. 1998, 264, 293–298
[16]Fujikane M., Kurosaki K., Muta H., Yamanaka S. J. Alloys Compd., 2005, 393, 299–301
[17]Rowe D. M. CRC Handbook of Thermoelectrics; CRC Press: Boca Raton, 1995
[18]Wang, Y. C., DiSalvo, and F. J. J. Solid State Chem. 2001, 156, 44-50
[19]Patschke R., Zhang X., Singh D., Schindler J., Kannewurf C. R., Lowhorn N., Tritt T., Nolas G.S., Kanatzidis M. G. Chem. Mater. 2001, 13, 613-621
[20]Assoud, A., Thomas, S., Sutherland, B., Zhang, H., Tritt, T. M., and Kleinke, H. Chem. Mater. 2006, 18, 3866.
[21]Cui, Y., Assoud, A., Xu, J., and Kleinke,H. Inorg. Chem. 2007, 46, 1215-1221
[22]Mayasree O., Cui Y. J., Assoud A., Kleinke H. Inorg. Chem. 2010, 49, 6518-6524
[23]Kuropatwa B. A., Assoud A., Kleinke H. Inorg. Chem. 2012, 51, 5299-5304
[24]Mayasree O., Sankar C. R., Cui Y., Assoud A., Kleinke H. Eur. J. Inorg. Chem. 2011, 4037-4042
[25]Mayasree O., Sankar C. R., Assoud A., Kleinke H. Inorg. Chem. 2011, 50, 4580-4585
[26]Kuropatwa B. A., Cui Y., Assoud A., Kleinke H., Chem. Mater. 2009, 21, 88-93
[27]Sootsman J. R., Kong H., Uher C., D’Angelo J. J., Chun-I Wu, Hogan T. P., Caillat T., Kanatzidis M. G. Angew. Chem. Int. Ed. 2008, 47, 8618-8622
[28]Mercouri G. Kanatzidis Chem. Mater. 2010, 22, 648-659
[29]Assoud A., Cui Y., Thomas S., Sutherland B., Kleinke H. J. Solid State Chem. 2008, 181, 2024-2030
[30]Cui Y., Assoud A., Kleinke H. Inorg. Chem. 2009, 48, 5313-5319
[31]Sheldrick, G. M., SHELXL-97, University of Göttingen, Germany,
1997.
[32]Pawley, G. S. J. Appl. Crystallogr. 1981, 14, 357
[33]McCusker, L. B., Von Dreele, R. B., Cox, D. E., Louer, D., Scardi, P. J. Appl. Cryatallogr. 1999, 32, 36-50
[34]Mehrotra P. K., Hoffmann R. Inorg. Chem. 1978, 17, 2187-2189
[35]Merz Jr. K. M., Hoffmann R. Inorg. Chem. 1988, 17, 2120-2127
[36]Pyykkö P. Chem. Rev. 1997, 97, 597-636
[37]Mayasree O., Sankar C. R., Kleinke K. M., Kleinke H. Coord. Chem. Rev. 2012, 256, 1377-1383