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| DC 欄位 | 值 | 語言 |
|---|---|---|
| dc.contributor.advisor | 陳政維(Jeng-Wei Chen) | |
| dc.contributor.author | Huai-Min Li | en |
| dc.contributor.author | 黎懷敏 | zh_TW |
| dc.date.accessioned | 2021-06-16T23:42:49Z | - |
| dc.date.available | 2014-11-20 | |
| dc.date.copyright | 2012-08-20 | |
| dc.date.issued | 2012 | |
| dc.date.submitted | 2012-07-24 | |
| dc.identifier.citation | References
1. D. L. Quintero-Castro1,2,*, B. Lake1,2, E. M. Wheeler1, A. T. M. N. Islam1, T. Guidi3, K. C. Rule1, Z. Izaola1, M. Russina1, K. Kiefer1, and Y. Skourski4 Phys. Rev. B 81, 014415 (2010) 2. Yogesh Singh and D. C. Johnston Phys. Rev. B 76, 012407 (2007) 3. M. C. Cross and Daniel S. Fisher* Phys. Rev. B 19, 402–419 (1979) 4. A. V. Sologubenko1, K. Gianno1, H. R. Ott1, U. Ammerahl2, and A. Revcolevschi2 Phys. Rev. Lett. 84, 2714–2717 (2000) 5. A. K. Kolezhuk, H.-J. Mikeska Phys. Rev. B 56, R11380–R11383 (1997) 6. Zhe Wang, M. Schmidt, A. Gunther, F. Mayr, Yuan Wan, S.-H. Lee, H. Ueda, Y. Ueda, A. Loidl, J. Deisenhofer Phys. Rev. B 83, 201102(R) (2011) 7. L.C. Chapon, C. Stock, P.G. Radaelli, C. Martin arXiv:0807.0877v2 (unpublished) Jul 10, (2012) 8. S. Chattopadhyay, S. Giri and S. Majumdar The European Physical Journal B Volume 85, Number 1 (2012), 9. M. Kofu1, H. Ueda2, H. Nojiri3, Y. Oshima3, T. Zenmoto3, K. C. Rule4, S. Gerischer4, B. Lake4,5, C. D. Batista6, Y. Ueda2, and S.-H. Lee1,* Phys. Rev. Lett. 102, 177204 (2009) 10. M. Fourmigue, L. Ouahab, Conducting and Magnetic Organometallic Molecular Materials (2009) 11. H. A. Jahn and E. Teller Proceedings of the Royal Society of London. Series A, Mathematical and Physical Sciences Page 220 of 220 – 235 (1937) 12. E. A. El-Rafei Inorg. Chem. , 20, 222-227 (1981) 13. Iztok Arcon, Breda Mirtic*, Alojz Kodre, J. Am. Ceram. Soc., 81 [1] 222–24 (1998) 14. A. K. JONSCHER* Nature 267, 673 - 679 23 June (1977) 15. Dirk Wulferding1, Peter Lemmens1, Kwang-Yong Choi2, Vladimir Gnezdilov3, Yurii G. Pashkevich4, Joachim Deisenhofer5, Diana Quintero-Castro6,7, A. T. M. Nazmul Islam6, and Bella Lake6,7 Phys. Rev. B 84, 064419 (2011) 16. A.A. Aczel, H.A. Dabkowskab, P.R. Provenchera, G.M. Lukea, b Journal of Crystal Growth Volume 310, Issue 4, Pages 870 - 873 15 February (2008) 17. H. Pausch and H. K. Mller-Buschbaum, Zeitschrift fr anorganische und allgemeine Chemie 405, 113 (1974) 18. Dirk Wulferding, Kwang-Yong Choi, Peter Lemmens, Alexey N. Ponomaryov, Johan van Tol, A. T. M. Nazmul Islam, Sandor Toth, Bella Lake arXiv:1205.3640v1 (unpublished) 16 May (2012) 19. S. Toth1,2,*, B. Lake1,2, S. A. J. Kimber3,1, O. Pieper1, M. Reehuis1, A. T. M. N. Islam1, O. Zaharko4, C. Ritter5, A. H. Hill3, H. Ryll1, K. Kiefer1, D. N. Argyriou1, and A. J. Williams6 Phys. Rev. B 84, 054452 (2011) 20. L.C. Chapon, P. Manuel, F. Damay, P. Toledano, V. hardy, C. Martin arXiv:1006.5678v1 (unpublished) 29 Jun (2010) 21. Hewlett-Packard Inc., Basics of Measuring the Dielectric Properties of Materials, Application Note 1217-1. 22. D. C. Sinclair F. D. Morrison, and A. R. West, J. Am. Ceram., Soc. 84, 31 (2001) | |
| dc.identifier.uri | http://tdr.lib.ntu.edu.tw/jspui/handle/123456789/65437 | - |
| dc.description.abstract | 摘 要
不同價位鉻的氧化物Ca2+Cr23+O42-, Ca22+Cr23+O52-, 和A32+Cr25+O82- (A = Ca、 Sr、Ba)以及Mn參雜濃度不同Sr3Cr2-xMnxO8(x = 0.0, 0.1, 0.2)之介電性質研究。這一系列的化合物是利用固態方法於不同的鍛燒溫度(TA)、退火過程，和不同的通氣鍛燒時間等製程以控制氧化程度。我們量測它們的介電性質並觀察它們的晶體結構. 藉由使用 X-ray 粉末分析法, 我們發現此系列化合物都同擁有相似的正交晶系結構,並且從最近的文獻中得知,降溫的過程中Ba3Cr2O8在70K以及Sr3Cr2O8在285K都存在一個六角晶系到單斜晶系的Jahn - Teller結構相變。我們以溫度和頻率作變數來量測介電常數(ε’)，介電損失(tan δ)，複數modulus (M’, M’’) 和 AC電導率以及磁化率來分析這些化合物的特性。除了Ca2Cr2O5，多數樣品在室溫下，可量到巨介電常數，而且發現這和晶體的結構有強關聯性，特別是Ba3Cr2O8在Jahn – Teller效應影響下的介電常數變化。另一個Sr3Cr2-xMnxO8(x = 0.0, 0.1, 0.2)系列，隨著Mn的參雜濃度提高，改變了晶格參數。 所有的樣品在ε’ (T) 的圖中，介電常數皆呈階梯式增加，並且皆對應一個峰值在 tan δ 圖中. 我們利用複數modulus 的計算來辨別出 grain 和 grain boundary 對整個介電系統的影響, 並發現在高溫時 grain boundary 對整個系統較 grain 佔有更大的影響. 目前在此篇論文的發現Ba3Cr2O8和Sr3Cr2O8在Jahn – Teller 結構相變之下，由於Ba3Cr2O8的 TJT = 70K 較Sr3Cr2O8的TJT = 285K更為低溫，是提供Jahn – Teller效應下，提供一個雜訊更少的環境的良好印證環境。Sr3Cr2-xMnxO8(x = 0.0, 0.1, 0.2)也因為參雜濃度改變，而改變了晶格參數，改變了介電常數量級。此外，Cr3+的CaCr2O4存在巨介電現象於接近室溫時(ε’~ 104)，並且發現介電常數展現另一個極大值~ 40 K 和長程反 鐵磁有序性有關，皆為介電性質提供更大的研究潛力。 | zh_TW |
| dc.description.abstract | Abstract
The synthesis, characterization and dielectric properties of polycrystalline alkaline earth chromates Ca2+Cr23+O42-, Ca22+Cr23+O52-, and A32+Cr25+O82- (A = Ca, Sr, and Ba) compounds were investigated. Powder X-ray diffraction patterns reveal that all the samples are single phase without any impurity. The dielectric properties of these compounds were studied in the frequency range from 20 Hz to 1 MHz between 20 K and 320 K. The Cr3+ valence contains CaCr2O4 sample exhibits a high dielectric permittivity (ε' ~ 104) at room temperature with frequency dispersion. In addition, ε'(T) also shows maxima at ~ 40 K. The corresponding tanδ (T) curves exhibit two relaxations at T < 40 K and ~ 260 K. The peak temperature TP of tanδ shifts to a higher temperature as the frequency increases in both relaxations. The overall behavior of high temperature ε' and tanδ is similar to that observed in giant dielectric constant materials. The observed giant dielectric response was explained in terms of internal (grain boundary) barrier layer capacitance (IBLC) effect and maxima at ~ 40 K is related to the development of long-range antiferromagnetic order. Moreover, calcium rich Cr3+ valence Ca2Cr2O5 sample shows very small value of ε' compare to the value of CaCr2O4. The ε'(T) curves of A3Cr2O8 (A = Ca, Sr, and Ba) samples reveal that the value of real dielectric permittivity decreases with increasing A-site ionic radius. The tanδ(T) curves of these compounds exhibit dielectric relaxation at high temperature. These peak temperatures also found to be decreased with increasing A-site ionic radius. The peak temperatures TP of tanδ shifts to a higher temperature as the frequency increases in all samples. The structural, orbital or spin fluctuations are likely origin for the observed results of Cr5+ valence compounds. | en |
| dc.description.provenance | Made available in DSpace on 2021-06-16T23:42:49Z (GMT). No. of bitstreams: 1 ntu-101-R99245018-1.pdf: 4457151 bytes, checksum: 2d3f566a1461d574f4afa6e2a4433b55 (MD5) Previous issue date: 2012 | en |
| dc.description.tableofcontents | Tables of Contents
誌 謝……………………………………………………………………………..….i 摘 要..........................................................................................................................ii Abstract………………………………………………………………………….……iii Table of Contents………………………………………………………………..……iv List of Pictures………………………………………………………………………..vi List of Tables………………………………………………………………………....xii Chapter 1 Introduction..............................................................................................1 Chapter 2 General Background.................................................................................5 a. Complex Permittivity.........................................................................................5 b. The Mechanism of Polarization.........................................................................7 c. Debye Equations...............................................................................................10 d. Arrhenius law...................................................................................................12 e. Bleaney-Bower model……………………………………………………......13 Chapter 3 Experimental Details…………………………………………………..14 A. Sample Preparation………………………………………………………….14 a.Ca3Cr2O8……………………………………………………………….14 b.Sr3Cr2O8..................................................................................................15 c.Ba3Cr2O8……………………………………………………………….16 d. Sr3Cr2-xMnxO8(x = 0.0, 0.1, 0.2)………………………………………..18 e.CaCr2O4………………………………………………………………...19 f.Ca2Cr2O5……………………………………………………………….20 B. X-ray diffraction…………………………………………………………….21 C. Dielectric Properties Measurement………………………………………….22 D. Jahn-Teller effect……………………………………………………………23 Chapter 4 Results and Discussion…………………………………………………..24 a. Ca3Cr2O8……………………………………………………………………...24 b. Sr3Cr2O8……………………………………………………………………....33 c. Ba3Cr2O8……………………………………………………………………...43 d. Sr3Cr1.95Mn0.05O8…………………………………………………………..54 e. Sr3Cr1.9Mn0.1O8……………………………………………………………..63 f. Sr3Cr1.8Mn0.2O8……………………………………………………………..72 g. CaCr2O4……………………………………………………………………....81 h. Ca2Cr2O5……………………………………………………………………..92 Chapter 5 Conclusion……………………………………………………………....98 References……………………………………………………………………………101 List of Pictures Fig. 4.a.1 X-ray diffraction pattern of the Ca3Cr2O8 compound with Miller indices of the peaks…………………………………………………………………………..27 Fig. 4.a.2 ε’-T of Ca3Cr2O8 sintered at 1200 °C……………………………………...28 Fig. 4.a.3 tanδ-T relation of Ca3Cr2O8 sintered at 1200 °C…………………………..28 Fig. 4.a.4 Activation energy values of Ca3Cr2O8 from Arrhenius plot……………….29 Fig. 4.a.5 M'-T relation Ca3Cr2O8 sintered at 1200 °C………………………………29 Fig. 4.a.6 Activation energy values of Ca3Cr2O8 from Arrhenius plot with M'-T relation………………………………………………………………………..30 Fig. 4.a.7 AC conductivity-f relation of Ca3Cr2O8 sintered at 1200 °C……………...30 Fig. 4.a.8 Fitting of AC conductivity of Ca3Cr2O8 sintered at 1200 °C……………...31 Fig. 4.a.9 Cole-Cole plot of Ca3Cr2O8 sintered at 1200 °C…………………………..31 Fig. 4.a.10 Cole-Cole plot of Ca3Cr2O8 sintered at 1200 °C........................................32 Fig. 4.a.11 Fitting of magnetic susceptibility for Ca3Cr2O8 measured under 1000 Oe……………………………………………………………….32 Fig. 4.b.1 X-ray diffraction pattern of the Sr3Cr2O8 compound with Miller indices of the peaks…………………………………………………………………………37 Fig. 4.b.2 ε’-T of Sr3Cr2O8 sintered at 1200 °C……………………………………..38 Fig. 4.b.3 tanδ-T relation of Sr3Cr2O8 sintered at 1200 °C………………………….38 Fig. 4.b.4 Activation energy values of Sr3Cr2O8 from Arrhenius plot………………...39 Fig. 4.b.5 M'-T relation Sr3Cr2O8 sintered at 1200 °C……………………………......39 Fig. 4.b.6 Activation energy values of Sr3Cr2O8 from Arrhenius plot with M'-T relation………………………………………………………………………...40 Fig. 4.b.7 AC conductivity-f relation of Sr3Cr2O8 sintered at 1200 °C……………....40 Fig. 4.b.8 Fitting of AC conductivity of Sr3Cr2O8 sintered at 1200 °C……………....41 Fig. 4.b.9 Cole-Cole plot of Sr3Cr2O8 sintered at 1200 °C...........................................41 Fig. 4.b.10 Cole-Cole plot of Sr3Cr2O8 sintered at 1200 °C……………………….....42 Fig. 4.b.11 Fitting of magnetic susceptibility for Sr3Cr2O8 measured under 1000 Oe………………………………………………………………..42 Fig. 4.c.1 X-ray diffraction pattern of the Ba3Cr2O8 compound with Miller indices of the peaks………………………………………………………….……………...47 Fig. 4.c.2 ε’-T of Ba3Cr2O8 sintered at 1200 °C………………………….…………48 Fig. 4.c.3 ε’-T of Ba3Cr2O8 with 8KOe magnetic field at different frequency which was intered at 1200°C…………………………………………………………48 Fig. 4.c.4 tanδ-T relation of Ba3Cr2O8 sintered at 1200 °C…………………………49 Fig. 4.c.5 Activation energy values of Ba3Cr2O8 from Arrhenius plot……………...49 Fig. 4.c.6 M'-T relation Ba3Cr2O8 sintered at 1200 °C……………………………..50 Fig. 4.c.7 Activation energy values of Ba3Cr2O8 from Arrhenius plot with M'-T relation…………………………………………………………………….....50 Fig. 4.c.8 AC conductivity-f relation of Ba3Cr2O8 sintered at 1200 °C……………..51 Fig. 4.c.9 Fitting of AC conductivity of Ba3Cr2O8 sintered at 1200 °C……………..51 Fig. 4.c.10 Cole-Cole plot of Ba3Cr2O8 sintered at 1200 °C………………………...52 Fig. 4.c.11 Cole-Cole plot of Ba3Cr2O8 sintered at 1200 °C………………………...52 Fig. 4.c.12 Fitting of magnetic susceptibility for Ba3Cr2O8 measured under 1000Oe……………………………………………………………………....53 Fig. 4.c.12’ Fitting of 1/x - T relation for Ba3Cr2O8 measured under 1000Oe…………………………………………………………………………....53 Fig. 4.d.1 X-ray diffraction pattern of the Sr3Cr1.95Mn0.05O8 compound with Miller indices of the peaks……………………………………………………….....57 Fig. 4.d.2 ε’-T of Sr3Cr1.95Mn0.05O8 sintered at 1200°C………………………........58 Fig. 4.d.3 tanδ-T relation of Sr3Cr1.95Mn0.05O8 sintered at 1200 °C………………...58 Fig. 4.d.4 Activation energy values of Sr3Cr1.95Mn0.05O8 from Arrhenius plot……..59 Fig. 4.d.6 Activation energy values of Sr3Cr1.95Mn0.05O8 from Arrhenius plot with M'-T relation……………………………………………………………...............60 Fig. 4.d.7 AC conductivity-f relation of Sr3Cr1.95Mn0.05O8 sintered at 1200°C.....60 Fig. 4.d.8 Fitting of AC conductivity of Sr3Cr1.95Mn0.05O8 sintered at 1200°C……...61 Fig. 4.d.9 Cole-Cole plot of Sr3Cr1.95Mn0.05O8 sintered at 1200 °C………………….61 Fig. 4.d.10 Cole-Cole plot of Sr3Cr1.95Mn0.05O8 sintered at 1200°C…………………62 Fig. 4.e.1 X-ray diffraction pattern of the Sr3Cr1.9Mn0.1O8 compound with Miller indices of the peaks………………………………………………………..................66 Fig. 4.e.2 ε’-T of Sr3Cr1.9Mn0.1O8 sintered at 1200 °C……………………………....67 Fig. 4.e.3 tanδ-T relation of Sr3Cr1.9Mn0.1O8 sintered at 1200 °C…………………...67 Fig. 4.e.4 Activation energy values of Sr3Cr1.9Mn0.1O8 from Arrhenius plot………..68 Fig. 4.e.5 M'-T relation Sr3Cr1.9Mn0.1O8 sintered at 1200 °C……………………….68 Fig. 4.e.6 Activation energy values of Sr3Cr1.9Mn0.1O8 from Arrhenius plot with M'-T relation……………………………………………………………………….69 Fig. 4.e.7 AC conductivity-f relation of Sr3Cr1.9Mn0.1O8 sintered at 1200 °C………69 Fig. 4.e.8 Fitting of AC conductivity of Sr3Cr1.9Mn0.1O8 sintered at 1200 °C………70 Fig. 4.e.9 Cole-Cole plot of Sr3Cr1.9Mn0.1O8 sintered at 1200 °C…………………...70 Fig. 4.e.10 Cole-Cole plot of Sr3Cr1.9Mn0.1O8 sintered at 1200 °C………………….71 Fig. 4.f.1 X-ray diffraction pattern of the Sr3Cr1.8Mn0.2O8 compound with Miller indices of the peaks………………………………………………………….75 Fig. 4.f.2 ε’-T of Sr3Cr1.8Mn0.2O8 sintered at 1200 °C……………………………...76 Fig. 4.f.3 tanδ-T relation of Sr3Cr1.8Mn0.2O8 sintered at 1200 °C…………………....76 Fig. 4.f.4 Activation energy values of Sr3Cr1.8Mn0.2O8 from Arrhenius plot…….......77 Fig. 4.f.5 M'-T relation Sr3Cr1.8Mn0.2O8 sintered at 1200 °C………………………..77 Fig. 4.f.6 Activation energy values of Sr3Cr1.8Mn0.2O8 from Arrhenius plot with M'-T relation………………………………………………………………………..78 Fig. 4.f.7 AC conductivity-f relation of Sr3Cr1.8Mn0.2O8 sintered at 1200 °C……….78 Fig. 4.f.8 Fitting of AC conductivity of Sr3Cr1.8Mn0.2O8 sintered at 1200 °C……….79 Fig. 4.f.9 Cole-Cole plot of Sr3Cr1.8Mn0.2O8 sintered at 1200 °C……………….......79 Fig. 4.f.10 Cole-Cole plot of Sr3Cr1.8Mn0.2O8 sintered at 1200 °C……………….....80 Fig.4.g.1 Crystal structure of CaCr2O4. CrO6 octahedral are shown in blue and green colors for the in equivalent Cr1 and Cr2 sites. The Ca2+ ions are shown as light grey spheres……………………………………………………………………………….84 Fig. 4.g.2 X-ray diffraction pattern of the CaCr2O4 compound with Miller indices of the peaks…………………………………………………………………............85 Fig. 4.g.3 ε’-T of CaCr2O4 sintered at 1200 °C…………………………………......86 Fig. 4.g.3’ ε’-T of CaCr2O4 sintered at 1200 °C……………………………….........86 Fig. 4.g.4 tanδ-T relation of CaCr2O4 sintered at 1200 °C……………………….....87 Fig. 4.g.4’ tanδ-T relation of CaCr2O4 sintered at 1200 °C………………………....87 Fig. 4.g.5 Activation energy values of CaCr2O4 from Arrhenius plot……………....88 Fig. 4.g.6 AC conductivity-f relation of CaCr2O4 sintered at 1200 °C………….......88 Fig. 4.g.6 AC conductivity-f relation of CaCr2O4 sintered at 1200 °C……………...89 Fig. 4.g.7 Fitting of AC conductivity of CaCr2O4 sintered at 1200 °C……………...89 Fig. 4.g.8 Cole-Cole plot of CaCr2O4 sintered at 1200 °C………………………….90 Fig. 4.g.9 Cole-Cole plot of CaCr2O4 sintered at 1200 °C………………………….90 Fig. 4.g.10 Temperature dependence of magnetic susceptibility for CaCr2O4 measured under 5000 Oe……………………………………………………………….91 Fig. 4.g.11 Fitting of 1/x - T relation for CaCr2O4 measured under 5000 Oe……....91 Fig. 4.h.1 X-ray diffraction pattern of the Ca2Cr2O5 compound with Miller indices of the peaks………………………………………………………………………...94 Fig. 4.h.2 ε’-T of Ca2Cr2O5 sintered at 1200 °C…………………………………....95 Fig. 4.h.3 tanδ-T relation of Ca2Cr2O5 sintered at 1200 °C………………………...95 Fig. 4.h.4 Activation energy values of Ca2Cr2O5 from Arrhenius plot……………..96 Fig. 4.h.5 Cole-Cole plot of Ca2Cr2O5 sintered at 1200 °C………………………...96 Fig. 4.h.6 Cole-Cole plot of Ca2Cr2O5 sintered at 1200 °C………………………...97 Fig. 4.h.7 Temperature dependence of magnetic susceptibility for Ca2Cr2O5 measured under 5000 Oe……………………………………………………………....97 List of Tables Table 4.a.1 The lattice constants of the Ca3Cr2O8 compound………………………..27 Table 4.b.1 The lattice constants of the Sr3Cr2O8 compound………………………...37 Table 4.c.1 The lattice constants of the Ba3Cr2O8 compound………………………..47 Table 4.d.1 The lattice constants of the Sr3Cr1.95Mn0.05O8 compound……………….57 Table 4.e.1 The lattice constants of the Sr3Cr1.9Mn0.1O8 compound…………………66 Table 4.f.1 The lattice constants of the Sr3Cr1.8Mn0.2O8 compound………………….75 Table 4.g.1 The lattice constants of the CaCr2O4 compound………………………...85 Table 4.h.1 The lattice constants of the Ca2Cr2O5 compound………………………..94 | |
| dc.language.iso | en | |
| dc.subject | 斜方晶體 | zh_TW |
| dc.subject | 電導率 | zh_TW |
| dc.subject | 介電常數 | zh_TW |
| dc.subject | 介電損失 | zh_TW |
| dc.subject | 反鐵磁相變 | zh_TW |
| dc.subject | Jahn - Teller Effect | en |
| dc.subject | dissipation factor | en |
| dc.subject | AC conductivity | en |
| dc.subject | Antiferromagnetic order | en |
| dc.subject | Spin-dimer | en |
| dc.subject | Dielectric constant | en |
| dc.title | 鹼土族鉻氧化物介電性質之研究 | zh_TW |
| dc.title | Dielectric Response of Alkaline Earth Chromates containing Cr3+ and Cr5+ compounds | en |
| dc.type | Thesis | |
| dc.date.schoolyear | 100-2 | |
| dc.description.degree | 碩士 | |
| dc.contributor.oralexamcommittee | 陳洋元(Yang-Yuan Chen),林昭吟(Jauyn-Grace Lin) | |
| dc.subject.keyword | 介電常數,斜方晶體,電導率,介電損失,反鐵磁相變, | zh_TW |
| dc.subject.keyword | Dielectric constant,dissipation factor,AC conductivity,Antiferromagnetic order,Spin-dimer,Jahn - Teller Effect, | en |
| dc.relation.page | 103 | |
| dc.rights.note | 有償授權 | |
| dc.date.accepted | 2012-07-25 | |
| dc.contributor.author-college | 理學院 | zh_TW |
| dc.contributor.author-dept | 應用物理所 | zh_TW |
| 顯示於系所單位： | 應用物理研究所 | |
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