N型庞磁电阻薄膜和钙钛矿氧化物异质结的制备及研究

项目名称： N型庞磁电阻薄膜和钙钛矿氧化物异质结的制备及研究

项目编号： No.10804005

项目类型： 青年科学基金项目

立项/批准年度： 2009

项目学科： 轻工业、手工业

项目作者： 段苹

作者单位： 北京工业大学

项目金额： 22万元

中文摘要： 首先，在成功制备La1-xSbxMnO3(x≤.1)和La1-xPrxMnO3陶瓷材料的基础上，用脉冲激光沉积方法在（100）LaAlO3和SrTiO3衬底生长了两种材料不同组分和厚度的薄膜。XRD和原子力显微镜检测结果表明所得薄膜为单向薄膜，并且薄膜的均方根粗糙度较低。对部分薄膜进行了电输运和磁性质的测试，结果表明薄膜具有良好的庞磁电阻效应，其中La0.8Pr0.2MnO3薄膜的磁电阻比率大约为1.8×3。对前期制备的La0.9Sb0.1MnO3体材料进行了电子自旋共振谱（ESR）和红外吸收谱（IR）的分析；ESR结果显示样品在较宽的温度范围多相共存；由IR发现材料在420和610cm-1附近具有明显的红外吸收峰，这两个峰来源于MnO6八面体的红外活性振动模ν#21644;ν#12290;吸收峰发生了不同程度的劈裂，来自ν#30340;峰劈裂宽度达66cm-1左右。结合ESR、IR结果表明体系中存在相分离现象。此外对La0.9Sb0.1MnO3薄膜的红外反射谱进行了测试，对La1-xPrxMnO3块材和通过柠檬酸法制备的钙钛矿氧化物 LaMn1-xFexO3样品进行了拉曼光谱的测试和研究。

中文关键词： La1-xSbxMnO3(x≤.1);La1-xPrxMnO3;庞磁电阻;相分离

英文摘要： La1-xSbxMnO3 (x≤.1) and La1-xPrxMnO3 thin films with different doped content and thickness were deposited on single-crystal LaAlO3 and SrTiO3 (001) substrates by pulsed laser deposition technique on the base of the ceramic compounds synthesized successfully by solid state reaction. The thin films have a perovskite single-phase structure from X-ray diffraction pattern, the root mean square (RMS) roughness of surface is little from the AFM results. The electrical transport and magnetic properties have been investigated for some thin films, The result indicate that the film perform the colossal magnetoresistance (CMR) effect, and the magnetoresistance ratio of 1.8*103% for La0.8Pr0.2MnO3 thin films is obtained at field of 5 T. The electron spin resonance (ESR) spectra and infrared absorption (IR) spectra of La1-xSbxMnO3 bulk have been studied. The ESR results demonstrate ferromagnetic and paramagnetic phases coexist in the wide transitional temperature range. The absorption peaks around 610 and 420cm-1 which come from infrared active vibrating modes νand νof MnO6 octahedron, respectively were found . The peaks split into several absorption peaks, and the peak near 610 cm-1 split into two peaks with the gap about 66 cm-1. The IR and ESR results indicate that there is phase separation in La1?xSbxMnO3 compounds. In addition, the reflectivity infrared (IR) spectra of La0.9Sb0.1MnO3 thin films are measured; the Rman spectra were measured and analyzed for LaMn1-xFexO3 obtained by polymerizable complex method and La1-xPrxMnO3 bulk.

英文关键词： La1-xSbxMnO3(x≤.1)；La1-xPrxMnO3；colossal magnetoresistance; phase separation