本研究針對具磁電交互作用的龐磁阻與多鐵性系之3d 金屬氧化物在電性及磁性的異常現象，以X 光及中子散射為主體來加以系統性的研究。 本研究將對此兩種應用性極高的磁電交互作用材料，分別以兩大部分來討論。在龐磁阻系統中的異常現象，在於元素摻雜鑭錳氧化物之龐磁阻薄膜,在基板應力效應造成相及磁轉變溫度改變與參雜元素有相反趨勢。 在多鐵性系統中，針對元素摻雜鈥錳氧化物在溫度90 至150K 出現未摻雜鈥錳氧化物未發現之鐵磁性叢集。根據研究，對於應力效應下元素摻雜鑭錳氧化物之龐磁阻薄膜在相及磁轉變溫度的改變，有兩種可能的原因。一個是锶的擴散從鈦酸锶基(SrTO3)至鑭鋇錳氧化物(La0.8Ba0.2MnO3)，造成部分薄膜轉換成鑭鋇鍶錳氧化物(La0.8(SryBa1-y)0.2MnO3)，導致相及磁轉變溫度的提高。因Sr 擴散而相及磁轉變溫度提高的薄膜，其原因在於過度的高溫退火及鈦酸锶基板表面不良造成。排除這兩項原因，我們專注於本質上的應力效應.根據在X 光繞射及吸收光譜的研究,我們發現,在鑭鋇錳氧化物(La0.8Ba0.2MnO3)薄膜系統裡,隨著薄膜的變薄應力的增加, 錳氧八面體(MnO6)會變成非常的對稱，引發動態的姜-泰勒效應.所以除了本來造成的鐵磁效應雙交換作用(Mn4+-O-Mn3+)以外,還有姜-泰勒效(Mn3+-O-Mn3+)。導致相及磁轉變溫度改變的 提高。 除了在磁性離子錳外，研究發現在摻雜離子鈣與鋇對氧的交互作用會有相
對性的改變, 龐磁阻系統的相及磁轉變溫度異常現象與摻雜的與鋇離子半徑的不同。
對多鐵性材料鈥鑭錳氧化物(Ho0.8La0.2Mn2O5)的鐵磁性 集的發生,在直流及交流的超導量子干涉磁量儀磁性量測與交流阻抗分析上,發現此溫度區間的磁性現象為類似超磁玻璃系統，而有著極化玻璃的特性. 在同樣的溫度區間的X 光散射
圖譜也發現新的繞射強度.但在中子繞射的分析裡，我們發現原子核結構沒有很巨大的變化。所以X 光繞射圖譜新的繞射強度,可能來至於新周期性的電子雲分佈在這個溫度區間會產生。 在中子繞射圖譜解析出的原子核位置，我們發現在延著晶格軸a 軸的錳氧八面體(MnO6)與錳氧金字塔(MnO5)的錳氧錳(Mn-O-Mn)較易會形成順磁態，而延著晶格軸b 軸的錳氧八面體(MnO6)與錳氧金字塔(MnO5)的錳氧錳 (Mn-O-Mn)較易會形成鐵磁態，所以勾勒出鐵磁性叢集可能出現在晶格軸b 軸的錳氧錳(Mn-O-Mn)。 在X 光吸收光譜研究中，我們從錳的L23 edge 吸收光譜，在90K~150K 溫度區間中發現在錳氧八面體(MnO6)與錳氧金字塔(MnO5)電子的分怖會有重新排列的現象。 從錳K edge 近吸收邊緣光譜,發現在這個特定溫區裡, 錳
與氧離子會因為錳 3d 與氧2p 與錳 4p 互相作用會增強，進而形成磁性訊息的傳遞,及電子雲的有序分怖。進而造成鐵磁性叢集及新的X 光繞射圖譜新的繞射強度出現. 我們歸納上述的研究，磁性及極化叢集可能在b 軸的錳氧八面體(MnO6)與錳
氧金字塔(MnO5) 錳氧錳(Mn-O-Mn)，磁性叢集間的作用力很小，而極化叢集有可能形成類似液晶態而形成新的周期性電子分佈。在鈥(Ho)與鑭(La)離子方面，從中子繞射的原子核結構分析，發現在此特定溫度區域鈥(Ho)與鑭(La)離子與氧的距離
有特別的變化，而氧的K edge 進吸收邊緣及La L3 延伸吸收光譜發現，在此特定溫度區域鈥(Ho)與鑭(La)離子氧的交互作用為不同的趨勢，所以對元素摻雜鑭錳氧化物的異常磁性電性叢集可能來至於鈥(Ho)與鑭(La)離子本質上的不同。

In this thesis, we have performed systematical study of anomalous electric and magnetic behaviors of the 3d transition metal oxides; colossal magnetoresistance (La1−xRxMnO3 where R is a divalent alkaline earth ion) and Multiferroic (Ho1-xLaxMn2O5) systems by X-ray and Neutron scattering techniques.
In our study, the enhancement of the transfer temperature for La0.8Ba0.2MnO3 under strain effect from the SrTiO3 substrate could be possible due to two reasons which one is Sr diffusion from SrTiO3 substructure, and other one is the octahedral MnO6 high symmetry are increasing. We focus the intrinsic strain effect on La0.67Ca0.33MnO3 and La0.8Ba0.2MnO3 films, and findings show that due to the different ionic sizes of doped Ca or Ba ions, the strain effect acts differently in the way it deforms. The interfacial strain effect produces opposite influences on the lattice symmetry, the average Mn–O bond lengths, the average oxygen disorders, the coupling symmetries inside and in the vicinity of the MnO6 octahedrons, as well as producing an opposing trend in metal-insulator and magnetic transition temperatures of the strained La0.67Ca0.33MnO3 and La0.8Ba0.2MnO3 films. The strain effects on the electronic structures of La0.67Ca0.33MnO3 and La0.8Ba0.2MnO3 thin films have been studied by O K-edge x-ray absorption near edge structure (XANES) spectroscopy. For La0.67Ca0.33MnO3, the first-principles calculations reveal that the features in the XANES spectra are associated with hybridized states between O 2p and Mn minority-spin 3d t2g and eg, La 5d/Ca 3d, and Mn 4s/Ca 4p states. An analysis of these features shows that the tensile strain decreases substantially La–O and Ca–O hybridization and TC for La0.67Ca0.33MnO3. For La0.8Ba0.2MnO3, the small compressive strain enhances slightly La–O and Ba–O hybridization and TC. In this thesis, the influence of the local structure distortion on the magnetic transition in La doped HoMn2O5 Multiferroics has been investigated systematically. The orthorhombic crystal structure of Ho1−xLaxMn2O5 is maintained up to x≦0.2 but decomposed into multiphase for x≧0.25. By doping La ions to a concentration of 0.1≦x≦0.2, the formation of the RMnO3 1(13) phase can be suppressed and single-phase Ho1−xLaxMn2O5 (0.1≦x≦0.2) compounds can be formed under 1 atm flowing oxygen. For x=0.2, a ferromagnetic FM transition at 150 K is superimposed on the paramagnetic background, which implies that the compound undergoes a ferromagnetic to antiferromagnetic (AFM) transition. This unique FM to AFM transition is observed for the first time. The FM transition is attributed to the formation of magnetic clusters in a host paramagnetic matrix. The anomalous magnetic clusters phenomena observed in Ho0.8La0.2Mn2O5 can be directly attributed to the different properties between Ho and La ions, and the differences of Ho and La ions are not only in the ionic radius but also in the electron negativity. During 90~150K, X-ray scattering diffraction presented the new addition peaks indicates the new electric density distribution, and the Neutron powder scattering diffraction (NPD) refining results show that the local structure of R-O (R: La, Ho) is un-symmetry which is conflict to the La Extended X-ray absorption fine structure (EXAFS) (which shows that the local structure of La-O becomes more symmetry than H-O. Since the refining values of the NPD are an average of entire crystal, such that it cannot tell the local changes. X-ray absorption spectrum (XAS) and EXAFS, in contrarily, can provide the local information. They implies that the temperature evolutions of the coupling strength with O 2p or unoccupied density state are opposite for the Ho and La ions in our Ho0.8La0.2Mn2O5 sample. Therefore, local change of ions position and charge redistribution happens in this specific temperature range.

Contents
Abstract (Chinese)-----------------------------------------------------Ⅰ
Abstract (English) -----------------------------------------------------Ⅲ
Contents -----------------------------------------------------------------Ⅴ
Figure List--------------------------------------------------------------Ⅵ
Table List ---------------------------------------------------------------Ⅷ
Chapter 1 Introductions
1-1Motivation and Research goals
1-1-1 Anomalous strain effect of the Colossal Magnetoresistance thin film-----------1
1-1-2 Anomalous electric and magnetic behaviors of the Multiferroics----------------4
Chapter 2 Review of Basic Theories
2-1 Double-Exchange mechanism-----------------------------------------------------------7
2-2 Jahn–Teller effects-----------------------------------------------------------------------10
2-3 Semicovalence-----------------------------------------------------------------------------13
Chapter 3 Theoretical background on experimental techniques and methods
3-1 Basics of x-ray scattering
3-1-1 Scattering by an electron-----------------------------------------------------------17
3-1-2 Scattering by an atom---------------------------------------------------------------21
3-1-3 Scattering by a small crystal-------------------------------------------------------26
3-2 Basic of Neutron diffraction
3-2-1 Neutron scattering cross-section--------------------------------------------------28
3-2-2 Coherent and incoherent scattering-----------------------------------------------31
3-2-3 Scattering functions (dynamic structure factor)---------------------------------32
3-2-4 Elastic, quasielastic and inelastic scattering-------------------------------------33
3-3 Basic of X-ray absorption spectrums---------------------------------------------------36
Chapter 4 Results and discussions
4-1 Anomalous strain effect of Ca and Ba doping of the LaMnO3 CMR thin films
4-1-1 Inter diffusion effect on strained La0.8Ba0.2MnO3 thin films by off-axis sputtering on SrTiO3 (100) substrates-------------------------------------------43
4-1-2 Particular strain relaxation for La0.67Ca0.33MnO3 and La0.8Ba0.2MnO3 films on SrTiO3 substrates---------------------------------------------------------------50
4-1-3 Effects of strain on the electronic structures and TC’s of the La0.67Ca0.33MnO3 and La0.8Ba0.2MnO3 thin films deposited on SrTiO3-------60
4-1-4 Ionic size effect deformation on MnO6 octahedrons in colossal magnetoresistance strain films----------------------------------------------------70
4-1-5 Section conclusion-------------------------------------------------------------------79
4-2 Anomalous magnetic phase effect of HoMn2O5 (La doping)
4-2-1 Sample preparation and confirmation of La doping HoMn2O5----------------82
4-2-2 Glass-like magnetic and electric properties of La doping HoMn2O5 analysis with Superconducting quantum interference device and LCR impedance
4-2-2-1 DC and AC Superconducting quantum interference device analysis------87
4-2-2-2 LCR impedance spectrums analysis--------------------------------------------98
4-2-3 Temperature dependence X-ray powder diffraction----------------------------103
4-2-4 Temperature dependence Neutron powder diffraction-------------------------110
4-2-5 Temperature dependence X-ray absorption spectrums
4-2-5-1 Mn K and L edge X-ray absorption spectrums--------------------------131
4-2-5-2 O K and La L3 edge X-ray absorption spectrums-----------------------144
4-2-6 Section conclusion-------------------------------------------------------------------156
Reference-----------------------------------------------------------------------------------------163
Appendices---------------------------------------------------------------------------------------169

1. H. A. Jahn and E. Teller, Proc. R. Soc. London, Ser. A 161, 220(1937).
2. G. Jonker and J. van Santen, Physica(Amsterdam) 16, 337 (1950).
3. J. van Santen and G. Jonker, Physica (Amsterdam) 16, 599 (1950).
4. C. Zener, Phys. Rev. 82, 403 (1951).
5. P.W. Anderson and H. Hasewaga, Phys. Rev. 100, 675 (1955).
6. A. J. Millis, Boris I. Shraiman, and R. Mueller, Phys. Rev. Lett. 77, 175(1996).
7. J. B. Goodenough, Phys. Rev. 100,564(1955)
8. J. B. Goodenough, A. Wold, N. Menyuk, and R. J. Arnott, Phys. Rev. 124, 373(1961).
9. J. B. Goodenough, Magnetism and the Chemical Bond (Wiley, New York, 1963).
10. G. F. Dionne, J. Appl. Phys. 79, 5172 (1996).
11. M. Imada, A. Fujimori, and Y. Tokura, Rev. Mod. Phys. 70, 1039 (1998).
12. Y. Tokura and Y. Tomioka, J. Magn. Magn. Mater. 200, 1 (1999).
13. E. L. Nagaev, Phys. Rep. 346, 387 (2001).
14. E. Dagotto, T. Hotta, and A. Moreo, Phys. Rep. 344, 1 (2001).
15. J. O’Donnell, M. S. Rzchowske, J. N. Eckstein, and I. Bozovic, Appl. Phys. Lett. 72, 1775(1998).
16. S. Freisem, A. Brockhoff, D. G. de Groot, B. Dam, and J. Arats, J. Magn. Magn. Mater. 165, 380 (1997).
17. E. Gommert, H. Cerva, J. Wecker, and K. Samwer, J. Appl. Phys. 85, 5417 (1999).
18. F. Tsui, M. C. Smoak, T. K. Nath, and C. B. Eom, Appl. Phys. Lett. 76, 2421 (2000).
19. B. Vengalis, A. Maneikis, F. Anisimovas, R. Butkuté, L. Dapkus, and A. Kindurys, J. Magn. Magn. Mater. 211, 35 (2000).
20. J. O’Donnell, M. Onellion, M. S. Rzchowski, J. N. Eckstein, and I. Bozovic, Phys. Rev. B 54, R6841(1996).
21. T. Kanki, H. Tanaka, and T. Kawai, Phys. Rev. B 64, 224418 (2001).
22. J. Zhang, H. Tanaka, T. Kanki, J.-H. Choi, and T. Kawai, Phys. Rev. B 64, 184404 (2001).
23. A. Miniotas, A. Vailionis, E. B. Svedberg, and U. O. Karlsson, J. Appl. Phys. 89, 2134 (2001).
24. H. Chou, M.-H. Tsai, F. P. Yuan, S. K. Hsu, C. B. Wu, J. Y. Lin, C. I. Tasi, and Y.-H. Tang, Appl. Phys. Lett. 89, 082511 (2006).
25. H. Schmid, Ferroelectrics 162, 317 (1994)
26. N. Hur, S. Park, P. A. Sharma, J. S. Ahn, S. Guha, and S.-W. Cheong, Nature (London) 419, 818 (2002)
27. N. Hur, S. Park, P. A. Sharma, S. Guha, and S.-W. Cheong, Phys. Rev. Lett. 93, 107207 (2004)
28. I. Kagomiya, K. Kohn, and T. Uchiyama, Ferroelectrics 280, 131 (2002)
29. W. Prellier, M. P. Singh, and P. Murugavel, J. Phys.: Condens. Matter 17, R803 (2005)
30. J. A. Alonso, M. T. Casais, M. J. Martínez-Lope, and I. Rasines, J. Solid State Chem. 129, 105 (1997)
31. J. A. Alonso, M. T. Casais, M. J. Martínez-Lope, J. L. Martínez, and M. T. Fernández-Díaz, J. Phys.: Condens. Matter 9, 8515 (1997)
32. V. A. Cherepanov, E. A. Filonova, V. I. Voronin, and I. F. Berger, J. Solid State Chem. 153, 205 (2000).
33. M. Kanai, H. Tanaka, and T. Kawai, Phys. Rev. B 70, 125109 (2004).
34. H. Chou, S. G. Hsu, C. B. Lin, and C. B. Wu, Appl. Phys. Lett. 90, 062501 (2007).
35. M.-H. Tsai, Y.-H. Tang, H. Chou, and J. B. Wu, e-print cond-mat/0604367 and the bottom two panels shown in Fig. 4 of this study.
36. Table of Periodic Properties of the Elements, (Sargent-Welch Scientific Company, Skokie, IL, 1980).
37. R. H. Mitchell, A. R. Chakhmouradian, and P. M. Woodward, Phys. Chem. Miner. 27, 583 (2000).
38. S. J. Hibble, S. P. Cooper, A. C. Hannon, I. D. Fawcett, and M. Greenblatt, J. Phys.: Condens. Matter 11, 9221 (1999).
39. R. V. Kasowski, M.-H. Tsai, T. N. Rhodin, and D. D. Chambliss, Phys. Rev. B 34, 2656 (1986).
40. M. Abbate, F. M. F. de Groot, J. C. Fuggle, A. Fujimori, O. Strebel, F. Lopez, M. Domke, G. Kaindl, G. A. Sawatzky, M. Takano, Y. Takeda, H. Eisaki, and S. Uchida, Phys. Rev. B 46, 4511 (1992).
41. M. Abbate, G. Zampieri, F. Prado, A. Caneiro, and A. R. B. de Castro, Solid State Commun. 111, 437 (1999).
42. E. Pellegrin, L. H. Tjeng, F. M. F. de Groot, R. Hesper, G. A. Sawatzky, Y. Moritomo, and Y. Tokura, J. Electron Spectrosc. Relat. Phenom. 86, 115 (1997).
43. J.-H. Park, T. Kimura, and Y. Tokura, Phys. Rev. B 58, R13330 (1998).
44. O. Toulemonde, F. Millange, F. Studer, B. Raveau, J.-H. Park, and C.-T. Chen, J. Phys.: Condens. Matter 11, 109(1999).
45. N. Mannella, A. Rosenhahn, M. Watanabe, B. Sell, A. Nambu, S. Ritchey, E. Arenholz, A. Young, Y. Tomioka, and C. S. Fadley, Phys. Rev. B 71, 125117(2005).
46. M. Newville, J. Synchrotron Radiat. 8, 322 (2001).
47. B. Ravel, J. Synchrotron Radiat. 8, 314 (2001).
48. B. Ravel and M. Newville, J. Synchrotron Radiat. 12, 537 (2005).
49. S. I. Zabinsky, A. Ankudinov, J. J. Rehr, and R. C. Albers, Phys. Rev. B 52, 2995 (1995).
50. D. Cao, F. Bridges, D. C. Worledge, C. H. Booth, and T. Geballe, Phys. Rev. B 61, 11373 (2000).
51. C. H. Booth, F. Bridges, G. H. Kwei, J. M. Lawrence, A. L. Cornelius, and J. J. Neumeier, Phys. Rev. Lett. 80, 853 (1998).
52. C. H. Booth, F. Bridges, G.H. Kwei, J.M. Lawrence, A.L. Cornelius, and J.J. Neumeier, Phys. Rev. B 57, 10440 (1998).
53. F. M. F. de Groot, M. Grioni, J. C. Fuggle, J. Ghijsen, G. A. Sawatzky, and H. Petersen, Phys. Rev. B 40, 5715 (1989).
54. H. Kurata and C. Colliex, Phys. Rev. B 48, 2102 (1993).
55. J. A. Alonso, M. T. Casais, M. J. Martínez-Lope, and I. Rasines, J. Solid State Chem. 129, 105 (1997)
56. J. A. Alonso, M. T. Casais, M. J. Martínez-Lope, J. L. Martínez, and M. T. Fernández-Díaz, J. Phys.: Condens. Matter 9, 8515 (1997)
57. J. L. Tholence, Physica B & C 108, 1287 (1981)
58. Hiroshi Furukawa, Phys. Rev. A 28, 1717 (1983)
59. Mydosh J 1993 Spin Glasses: An Experimental Introduction (London: Taylor and Francis)
60. Hohenberg P C and Halpcrin B I, Rev. Mod. Phys. 49 435 (1977)
61. Ogielski A T, Phys. Rev. B 32 7384 (1985)
62. Jönsson, P. E.; Hansen, M. F.; Nordblad, P. Phys. Rev. B, 61, 1261(2000)
63. Bedanta, S.; Klemann, W. J. Phys. D: Appl. Phys., 42, 013001 (2009)
64. Jönsson, P. E. J. Nanosci. Nanotechnol., 10, 6067(2010)
65. G. Lawes, B. Melot, K. Page, C. Ederer, M. A. Hayward, Th. Proffen, and R. Seshadri, Phys. Rev. B 74, 024413 (2006)
66. V. A. Sanina, E. 1. Golovenchits, and G. A. Smolenskïí ,Pis'ma Zh. Eksp. Teor. Fiz. 40,110 (1984)
67. A.C. Larson and R.B. Von Dreele, Los Alamos National Laboratory Report LAUR 86-748 (1994).
68. B. H. Toby, J. Appl. Cryst. (2001). 34, 210.
69. Alonso J A, Casais M T, Martínez-Lope M J, Martínez J L and Fernández-Díazz M T, J. Phys.: Condens. Matter 9, 8515 (1997).
70. G. R. Blake1,2, L. C. Chapon1, P. G. Radaelli1,3, S. Park4, N. Hur4, S-W. Cheong4, and J. Rodríguez-Carvajal, Phys. Rev. B 71, 214402 (2005).
71. Junjiro Kanamori, J. Phys. Chem. Solids, 10. 87 (1959)
72. F. Bridges, C. H. Booth, G. H. Kwei, J. J. Neumeier ,G. A. Sawatzky Physical Review B, 61, R9237