多鐵材料Co3-xCuxTeO6 (x = 0.09, 0.15, 0.18) 之磁有序參數分析

Please use this identifier to cite or link to this item: http://ir.lib.ncu.edu.tw/handle/987654321/80700

Title:	多鐵材料Co3-xCuxTeO6 (x = 0.09, 0.15, 0.18) 之磁有序參數分析
Authors:	林廷軒;Lin, Ting-Syaun
Contributors:	物理學系
Keywords:	多鐵材料;有序參數;磁電耦合;中子繞射;公度自旋;非公度自旋;multiferroics;propagation vector;magnetoelectric coupling;neutron scattering;commensurate spin;incommensurate spin
Date:	2019-07-04
Issue Date:	2019-09-03 14:59:56 (UTC+8)
Publisher:	國立中央大學
Abstract:	近年來，由於科技的突破，新穎的多鐵材料紛紛被合成出來，自2005年科學家開始投入研究多鐵材料，而第二類多鐵材料因其鐵電性與鐵磁性能交互影響，此系統材料擁有非常顯著且豐富的相變物理特性，科學家們提出大量的實驗方法探討其物理現象，也提出相關理論來描述該系統，例如簡單公度自旋(simple commensurate spin)、複雜非公度自旋(complex incommensurate spin)、自發極化與磁電耦合。　　此篇論文將討論M3TeO6系統中M為Co與Cu以不同摻雜比例之物理特性以及磁相變，首先利用固態反應法製程，製備出Co3-xCuxTeO6樣品，其中x =0.09、0.15、0.18，由磁化率對溫度趨勢圖中，三組樣品皆有呈現反鐵磁與鐵磁特性，並使用澳洲ANSTO兩台中子粉末繞射儀，透過高解析度中子粉末繞射儀確定晶體結構及各樣品之鈷與銅比例，且藉由擬合得知摻雜之銅離子大多在Co-Chain上，結構上佔有百分率從4.4%到11.6%。而透過高強度中子粉末繞射儀。在低溫(3.5 K)時觀察到明顯的ICM peaks，隨溫度上升發現CM peaks與不同的ICM peaks。 Co3-xCuxTeO6系統擁有著複雜又豐富的磁性、電性與磁電耦合等物理特性，此篇論文主要研究不同銅摻雜比例的Co3-xCuxTeO6樣品之磁特性、CM magnetic order、ICM magnetic order與對應之propagation vector q值之計算與探討。 ;Due to the breakthrough of science and technology recently, novel multiferroic materials have been synthesized, scientists have been researching multiferroic materials since 2005, and the second type of multiferroic materials has significant physical properties and complex phase-change physical properties, scientists proposed a lot of experimental methods to explore the material’s physical phenomena, and also proposed relevant theories to describe the system, such as simple commensurate spin, complex incommensurate spin, spontaneous polarization and magnetoelectric coupling. This thesis discusses about the physical properties and magnetic phase transition of M in M3TeO6 systems with different doping ratio. First, we use the solid-state reaction process to synthesize Co3-xCuxTeO6 samples, where x = 0.09, 0.15, and 0.18. In the AC magnetic susceptibility versus temperature trend graph, all three samples exhibited antiferromagnetic characteristics, and we also use two neutron powder diffractometers in Australia ANSTO, to determine the samples crystal structure, and the cobalt/copper ratio of each sample through the high-resolution neutron powder diffractometer. The percentage of the composition in copper on each sample is known by GSAS fitting. And we also used the high-intensity neutron powder diffractometer to observe the significant ICM peaks which at low temperature (3.5 K), and CM peaks and another different ICM peaks which are found at different temperature. The system of Co3-xCuxTeO6 have complex and rich physical properties such as magnetic, electrical and magnetoelectric coupling. This thesis mainly studies about the magnetic properties of Co3-xCuxTeO6 with different copper-doping ratios, CM magnetic order, ICM magnetic order and the calculation and discussion of the propagation vector q value of Co3-xCuxTeO6, x=0.09, 0.15, 0.18.
Appears in Collections:	[Graduate Institute of Physics] Electronic Thesis & Dissertation

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