摻雜鋱錳氧化物之磁性與介電性質研究 = Study of magneti...
國立高雄大學應用物理學系碩士班

 

  • 摻雜鋱錳氧化物之磁性與介電性質研究 = Study of magnetic and dielectric properties of doped TbMnO3
  • 紀錄類型: 書目-語言資料,印刷品 : 單行本
    並列題名: Study of magnetic and dielectric properties of doped TbMnO3
    作者: 許旭均,
    其他團體作者: 國立高雄大學
    出版地: [高雄市]
    出版者: 國立高雄大學;
    出版年: 2015[民104]
    面頁冊數: [10],72面圖,表 : 30公分;
    標題: 鋱錳氧化物
    標題: TbMnO3
    電子資源: https://hdl.handle.net/11296/4cyd2u
    附註: 109年11月18日公開
    摘要註: 本研究利用固態反應法(solid-state reaction method)製備Tb1-xYxMnO3 (0.0 ≤ x ≤ 0.15)與Tb1-xHoxMnO3 (0.0 ≤ x ≤ 0.15)兩系列之鋱錳氧化物塊材樣品,並量測其微觀結構、磁性質與介電性質,希望藉此能清楚探討釔和鈥摻雜對鋱錳氧化物物理性質之影響。樣品之微觀結構是以X-ray繞射分析儀(X-ray diffraction; XRD)進行分析。而樣品之磁性質則利用超導量子干涉儀(Superconducting Quantum Interference Device Magnetometer; SQUID)來測量。我們還以電容/電感/電阻表(LCR meter)來測量樣品的介電性質。從XRD之結果得知,Tb1-xYxMnO3 (0.0 ≤ x ≤ 0.15) 塊材樣品皆為單一相的正交鈣鈦礦結構,且隨著釔含量增加,樣品的晶格常數亦隨之減少。由磁性質分析發現,Tb1-xYxMnO3 (x = 0.0及x = 0.15) 樣品隨著Y的摻雜,樣品的磁化量會減少。另外,我們發現Tb3+磁矩翻轉所需要的外加磁場,則由於Y的摻雜而從16 kOe (x = 0)降為15 kOe (x = 0.15)。在介電特性分析發現,Tb1-xYxMnO3 (0.0 ≤ x ≤ 0.15) 樣品皆具有一個介電鬆弛峰,我們利用阿瑞尼士方程式擬合可得各樣品的活化能約為0.24 ~ 0.27 eV。我們推論樣品的介電鬆弛行為主要來自於晶界的IBLC效應。此外,從XRD之結果也發現,Tb1-xHoxMnO3 (0.0 ≤ x ≤ 0.15) 塊材樣品皆為單一相的正交鈣鈦礦結構,且隨著Ho含量增加,樣品的晶格常數也隨之減少。由磁性質分析顯示,Tb1-xHoxMnO3 (0.0 ≤ x ≤ 0.15) 樣品隨著Ho摻雜濃度漸增,樣品的磁化量也會隨之增加。同時,我們發現Tb1-xHoxMnO3 (0.0 ≤ x ≤ 0.15)樣品也具有介電鬆弛之現象,而且Tb0.85Ho0.15MnO3 樣品具有較高的介電常數(~14000)以及較低的介電損耗。 In this study, we prepared two series of Tb1-xYxMnO3 (0.0 ≤ x ≤ 0.15) and Tb1-xHoxMnO3 (0.0 ≤ x ≤ 0.15) bulk samples by solid-state reaction method. Owing to study the magnetic and dielectric properties of Yttrium (Y) or Holmium (Ho) doped TbMnO3 samples; we measured their microstructure, magnetic and electrical properties. The crystalline structures of samples were examined by X-ray diffraction (XRD). The magnetization measurements were carried out using the Superconducting Quantum Interference Device (SQUID) magnetometer. The dielectric properties measurements were performed using a LCR meter. From the results of XRD patterns of the Tb1-xYxMnO3 (0.0 ≤ x ≤ 0.15) samples, all the observed peaks can be indexed in orthorhombic perovskite structures. Lattice parameters a and c change systematically with increasing Y content (x) implies that the Y-ions do replace the Tb-ions. The magnetization M(H) of Tb1-xYxMnO3 (0.0 ≤ x ≤ 0.15) samples, showing the magnetization decreases with increasing the Y-content. The magnetic characterization indicates that with increasing Y-content, up to 0.15, the metamagnetic transition field of Tb3+ decreased from 16 kOe to 15 kOe. The dielectric spectrum of the Tb1-xYxMnO3 (0.0 ≤ x ≤ 0.15) samples, showing a dielectric loss peak which follows the Arrhenius behavior that gives the activation energy between 0.24 ~ 0.27 eV, close to the IBLC effects associated with the grain boundaries. Furthermore, the sample of Tb0.95Y0.05MnO3 presents the largest dielectric constants at low frequency. We also observed all Tb1-xHoxMnO3 (0.0 ≤ x ≤ 0.15) samples with orthorhombic perovskite structures. The substitution of Tb3+ by Ho3+ leads to lattice contraction due to the smaller ionic radius of Ho3+ than Tb3+. The magnetic characterization indicates that with an increase in the Ho-content, the magnetization of Tb1-xHoxMnO3 (0.0 ≤ x ≤ 0.15) increases. Moreover, the dielectric spectrum was also obtained, the Ho-doped TbMnO3 samples exhibit the only one relaxation behavior that associated with the IBLC effects related to the grain boundaries. Furthermore, the sample of Tb0.85Ho0.15MnO3 presents the largest dielectric constants (~14000) and lowest dielectric loss at low frequency.
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310002931254 博碩士論文區(二樓) 不外借資料 學位論文 TH 008M/0019 423203 0844 2015 一般使用(Normal) 在架 0
310002931262 博碩士論文區(二樓) 不外借資料 學位論文 TH 008M/0019 423203 0844 2015 c.2 一般使用(Normal) 在架 0
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