| 非晶态分子合金低温制备纳米复合氧化物La~1~-~xCa~xMnO~3 |
| |
| 引用本文： | 易涛,高松,戚星.非晶态分子合金低温制备纳米复合氧化物La~1~-~xCa~xMnO~3[J].化学学报,2000,58(2):162-166. |
| |
| 作者姓名： | 易涛 高松 戚星 |
| |
| 作者单位： | [1]北京大学稀土材料化学及应用国家重点实验室 [2]清华大学化学系分析中心 |
| |
| 基金项目： | 本课题获国家自然科学基金(29771001,29525101)，国家重点基础研究发展规划项目，教育部博士学科点基金(97000117)，北京大学方正集团资助 |
| |
| 摘 要： | 钙钛矿型稀土锰氧化物La~1~-~xCa~xMnO~3(RE=La,Pr,Nd,Gd;T=Ca,Sr,Ba,Pb等)因其特殊的巨磁电阻效应,引起人们广泛的关注。用非晶态的分子合金为前驱体,制备了一系列具有纳米尺寸的La-Ca-Mn-O复合氧化物颗粒。研究表明,前驱体的晶化温度对纳米颗粒的形貌和大小均有影响。当晶化温度为450℃-600℃时,从透射电子显微镜观察到的颗粒大小约为25nm-100nm。该纳米材料的磁及磁电阻行为不同于其体相体系,其交流磁化率表现出较较强的尺寸依赖性,而磁电阻具有本征型和自旋隧穿型的巨磁电阻行为。
|
| 关 键 词： | 非晶体材料 纳米相材料 氧化镧 氧化钙 氧化锰 复氧化物 钙钛矿型结构 透射电子显微术 磁化强度 |
| 修稿时间： | 1999-03-09 |
Low temperature synthesis of nanosized La~1~-~xCa~xMnO~3 using amorphous molecular alloys as precursors |
| |
| YI Tao ,GAO Song ,QI Xing
ZHU Yong-Fa
HUANG Yun-Hui ,CHENG Fu-Xiang.Low temperature synthesis of nanosized La~1~-~xCa~xMnO~3 using amorphous molecular alloys as precursors[J].Acta Chimica Sinica,2000,58(2):162-166. |
| |
| Authors: | YI Tao GAO Song QI Xing
ZHU Yong-Fa
HUANG Yun-Hui CHENG Fu-Xiang |
| |
| Institution: | YI Tao ,GAO Song ,QI Xing
(State Key Laboratory of Rare Earth Materials Chemistry and Appliations,College of
Chemistry and Moleular Engineering, Peking University, Beijing,100871)
ZHU Yong-Fa
(Department of Chemistry, Tsinghua University, Beijing, 100084)
HUANG Yun-Hui ,CHENG Fu-Xiang
(State Key Laboratory of Rare Earth Materials Chemistry and Appliations,College of
Chemistry and Moleular Engineering, Peking University, Beijing,100871) |
| |
| Abstract: | Perovskite manganates of the type La~1~-~xCa~xMnO~3 is of considerable interest in solid state physics and chemistry because of its special magneto-transport properties, colossal magnetoresistance (CMR) effect. We reported here a new route to the nanosized La~1~- ~xCa~xMnO~3 perovskite crystalline complex oxides at relatively low calcination temperature (450℃-600℃) using amorphous molecular alloys of La-Ga-Mn-DTPA as precursors. The size and topography of the oxides are dependent on the annealing temperature of the precursors. The particle size is, ranging from 25nm to 100nm determined by TEM under calcinating temperature of 450℃ to 600℃. The AC susceptibility is found to be strongly dependent on the particle size. Preliminary magnetoresistance research on pellet sample shows spin- polarized tunneling behavior at low temperature range. |
| |
| Keywords: | colossal magneto - resistance ( CMR) amorphous molecular alloy nano complex oxide AC susceptibility spin - polarized tunneling |
| 本文献已被 CNKI 维普 万方数据 等数据库收录！ |
| 点击此处可从《化学学报》浏览原始摘要信息 |
| 点击此处可从《化学学报》下载免费的PDF全文 |
|
