Structure and properties of (R0.5A0.5)BO3 (R = Gd, Yb; A = Ca, Sr; B = Mn, Ti or A = Ce, Th; B = Ni) oxides
碩士 === 淡江大學 === 化學學系碩士班 === 93 === 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....
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ndltd-TW-093TKU050650352015-10-13T11:57:26Z http://ndltd.ncl.edu.tw/handle/90215289951503321002 Structure and properties of (R0.5A0.5)BO3 (R = Gd, Yb; A = Ca, Sr; B = Mn, Ti or A = Ce, Th; B = Ni) oxides (R0.5A0.5)BO3(R=Gd,Yb;A=Ca,Sr;B=Mn,TiorA=Ce,Th;B=Ni)氧化物的結構與特性研究 Chun-wei Chen 陳俊瑋 碩士 淡江大學 化學學系碩士班 93 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. Huey-Chuen I. Kao 高惠春 2005 學位論文 ; thesis 151 zh-TW |
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碩士 === 淡江大學 === 化學學系碩士班 === 93 === 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.
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author2 |
Huey-Chuen I. Kao |
author_facet |
Huey-Chuen I. Kao Chun-wei Chen 陳俊瑋 |
author |
Chun-wei Chen 陳俊瑋 |
spellingShingle |
Chun-wei Chen 陳俊瑋 Structure and properties of (R0.5A0.5)BO3 (R = Gd, Yb; A = Ca, Sr; B = Mn, Ti or A = Ce, Th; B = Ni) oxides |
author_sort |
Chun-wei Chen |
title |
Structure and properties of (R0.5A0.5)BO3 (R = Gd, Yb; A = Ca, Sr; B = Mn, Ti or A = Ce, Th; B = Ni) oxides |
title_short |
Structure and properties of (R0.5A0.5)BO3 (R = Gd, Yb; A = Ca, Sr; B = Mn, Ti or A = Ce, Th; B = Ni) oxides |
title_full |
Structure and properties of (R0.5A0.5)BO3 (R = Gd, Yb; A = Ca, Sr; B = Mn, Ti or A = Ce, Th; B = Ni) oxides |
title_fullStr |
Structure and properties of (R0.5A0.5)BO3 (R = Gd, Yb; A = Ca, Sr; B = Mn, Ti or A = Ce, Th; B = Ni) oxides |
title_full_unstemmed |
Structure and properties of (R0.5A0.5)BO3 (R = Gd, Yb; A = Ca, Sr; B = Mn, Ti or A = Ce, Th; B = Ni) oxides |
title_sort |
structure and properties of (r0.5a0.5)bo3 (r = gd, yb; a = ca, sr; b = mn, ti or a = ce, th; b = ni) oxides |
publishDate |
2005 |
url |
http://ndltd.ncl.edu.tw/handle/90215289951503321002 |
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