【作者】 陈蕊；

【导师】 冯守华；

【作者基本信息】 吉林大学 ， 无机化学， 2013， 博士

【摘要】 本文致力于用化学溶液沉积法制备具有钙钛矿结构的锰氧化物薄膜材料，并提高其居里温度及磁电阻等相关物理性质。具体如下：第一章为绪论，主要介绍了钙钛矿锰氧化物材料的相关的基本概念，磁性及磁电阻的重要性，钙钛矿锰氧化物研究中所应用到的重要理论；第二章主要介绍应用化学溶液沉积法制备薄膜的合成过程及应用到的测试方法；第三章用化学溶液沉积法在单晶S（i100）基片上制备了La_1-xK_xMnO₃（x=0.05，0.10，0.15，0.20）和La_0.95-xCa_0.05K_xMnO₃（x=0.05，0.10，0.15，0.20）两个系列的薄膜，并对其结构与磁性进行分析；第四章主要在LAO（100）制备了La_1-xK_xMnO₃系列薄膜，发现了K元素的掺杂提高了母体的居里温度，并且研究了Mn⁴⁺/Mn³⁺比例对样品的物理性质的影响；第五章主要在LAO （100）制备了La_0.95-xCa_0.05K_xMnO₃薄膜；第六章运用化学溶液沉积法制备了具有多铁性质的BiFeO₃薄膜，并对其结构和铁电性进行了研究；第七章是对本论文工作的总结和展望，对下一步进行钙钛矿/铁电复合薄膜的设想。更多还原

【Abstract】 Perovskite manganites with a chemical formula of La_1-xA_xMnO₃（A is an alkalineearth element or alkaline element） exhibit various properties such as colossalmagnetoresistance （CMR） effect, Jahn-Teller Distortion, the charge orbital ordering,phase separation and metal-insulator transition, which show promising applications inmagnetic field sensors, hard disk read heads, and memory cells. CMR is due to thedouble exchange （DE） effects following a ferromagnetic coupling between Mn³⁺andMn⁴⁺ions. As a result, the tuning for the ratios of Mn³⁺/Mn⁴⁺becomes especiallynecessary in synthetic chemistry. In a number of doping manganites, the divalentelement dopants are studied. Accordingly, the studies of monovalent element dopingwhich may greatly change the ratios of Mn³⁺/Mn⁴⁺are followed recently. In this work,we deposit the doped LaMnO3and BiFeO₃multiferroics films and have a study onthe structural and physical properties. The main work are summarized as follows:1. The rhombohedra La_1-xK_xMnO₃（x=0.05,0.10,0.15and0.20） andLa_0.95-xCa_0.05K_xMnO₃（x=0.05,0.10,0.15and0.20） films are fabricated on single Si（100） substrate by chemical solution deposition （CSD） method. And there is no CMReffects in these films.2. The cubic perovskite thin films of La_1-xK_xMnO₃（x=0.05,0.1,0.15and0.20） on thesingle crystal LaAlO3substrate are prepared by CSD method. The thin films arehighly oriented along （h00） and the concentration of K dopants dominates the ratiosof Mn⁴⁺/Mn³⁺in the thin films. The value of Mn⁴⁺/Mn³⁺increases with increasing Kcontent, which results in the increasing Tcand insulator-metal temperature （TIM） with x. The maximum magnetoresistance ratio is44.7%at240K and2.0T for the x=0.05sample.3. The cubic perovskite thin films of La_0.95-xCa_0.05K_xMnO₃/LAO （x=0.05,0.10,0.15and0.20） are prepared by CSD method. The values of Tcand TIMcan be increased bycodoping K in La0.95Ca0.05MnO3. The magnetic entropy change increases withincreasing x, the maximum of the films is0.398kJ/K when x=0.15.4. BiFeO₃films are grown on ITO/glass substrate by CSD method. It is found that thefilms growth along （101） crystal orientation and have a plat and smooth surface. Thefilms present ferromagnetic behavior, the magnetization easy axis is along （101）. Thesaturation polarization is about51.3μC/cm².更多还原