- 學位論文
(R0.5A0.5)BO3 (R = Gd, Yb; A = Ca, Sr; B = Mn, Ti or A = Ce, Th; B = Ni)氧化物的結構與特性研究
Structure and properties of (R0.5A0.5)BO3 (R = Gd, Yb; A = Ca, Sr; B = Mn, Ti or A = Ce, Th; B = Ni) oxides
摘要
本研究使用聚合的檸檬酸鹽先驅物法製備(R0.5A0.5)MnO3(R = Gd, Yb; A = Ca, Sr)與(R0.5A0.5)NiO3(A = Ce, Th)樣品，使用固態法製備(R0.5A0.5)TiO3 (A = Ca, Sr)。(R0.5A0.5)MnO3系列為正交晶系；(R0.5A0.5)NiO3系列為單斜晶系。SEM圖譜顯示利用檸檬酸鹽先驅物法製備的樣品，都具有較好的均勻度，而且樣品顆粒半徑較小。經由固態法製備的樣品則粒徑較大。經由XANES光譜判定Mn及Ti都具有3價與4價的混合價數。(R0.5A0.5)MnO3系列樣品皆為絕緣態，並具有類似自旋玻璃態的性質，FC與ZFC之變溫磁化率呈現不可逆的現象。所有樣品皆有負磁阻，且爐冷樣品的磁阻較驟冷樣品為高。(R0.5A0.5)MnO3系列樣品之磁阻值在80-100 K時約為60-65%。(R0.5A0.5)NiO3系列樣品呈現順磁金屬性，最大磁阻值溫度在200 K左右，約在50-60%。(R0.5A0.5)TiO3系列樣品為順磁性，並為Mott絕緣體。
並列摘要
In this research, homogeneous (R0.5A0.5)MnO3 (R = Gd, Yb; A = Ca, Sr) and (R0.5A0.5)NiO3 (A = Ce, Th) compounds with perovskite structure were synthesized by a polymeric citrate precursor method. (R0.5A0.5)TiO3 (A = Ca, Sr) was synthesized by a solid state method. (R0.5A0.5)MnO3 series samples have orthorhombic symmetry and (R0.5A0.5)NiO3 have monoclinic symmetry. The samples prepared by the polymeric citrate precursor method has a better homogeneity and the grain size is smaller than that prepared by the solid state method. Mn and Ti samples have M3+ and M4+ mixed valence state observed by XANES. The (R0.5A0.5)MnO3 samples are insulator, they has a spin-glass like property and the FC and ZFC susceptibility is irreversible. The (R0.5A0.5)NiO3 samples are paramagnetic metal. At 1 T magnetic field, both (R0.5A0.5)MnO3 and (R0.5A0.5)NiO3 have negative magnetoresistance (MR) ratio. The maximum MR ratio of (Gd0.5Ca0.5)MnO3 sample is found at 80-100 K,with a range of 60-65%. The maximum MR ratio of (R0.5A0.5)NiO3 sample is found at 180-200 K, with a range of 50- 60%. The (R0.5A0.5)TiO3 samples are paramagnetic Mott insulator.
參考文獻
延伸閱讀
- Wu, C. H. (2007). ACu3Ti4O12氧化物介電性質之研究 (A = Ca, La, Nd, Gd) [master's thesis, National Taiwan University]. Airiti Library. https://doi.org/10.6342/NTU.2007.02964
- Chen, C. Y. (2020). 以光譜實驗技術探究鈣鈦礦氧化物SrFeO3-δ, Ba2CuTeO6, 及 Li2Ni(WO4)2的電子結構與晶格動力學 [doctoral dissertation, National Taiwan Normal University]. Airiti Library. https://doi.org/10.6345/NTNU202001198
- 李阮鴻（2012）。R2(Zr,Ti)2O7 (R = Y、Gd、Sm、Nd) 氧化物及其與 (Li/Na)2CO3 複合材料之導電度研究〔碩士論文，淡江大學〕。華藝線上圖書館。https://doi.org/10.6846/TKU.2012.00992
- 魏珮伊、王玉瑞、王錫福、葉俊廷（2010）。Characteristic Properties of Mn Doped La0.6Sr0.4Co0.2Fe0.8O3-δ IT-SOFC Cathode Materials。鑛冶：中國鑛冶工程學會會刊，54(2)，68-74。https://doi.org/10.30069/MM.201006.0006
- Lien, C. Y., Kao, H. C. I., Ling, D. C., Lu, H. H., Chen, J. M., & Lee, J. M. (2005). Structure and Superconductivity of Bi2(Sr2−xMx)CuO6 (M = La, Gd, Y) Compounds. Chinese Journal of Physics, 43(3S), 629-637. https://www.airitilibrary.com/Article/Detail?DocID=05779073-200506-201210080013-201210080013-629-637