摘要钙钛矿结构的ReFeO3（Re代表稀土）是一类重要的材料，具有铁磁、磁光等优良性质。他们在燃料电池、催化剂、气敏材料、半导体材料、磁光材料等领域有着广泛的应用。我们在制备与磁性能方面的研究有益于它将来在是实际中的应用。27806
本实验通过优化工艺，采用溶胶-凝胶自蔓延燃烧法制备了一系列正交钙钛矿结构的DyFeO3纳米粉体。当柠檬酸与金属硝酸盐的比例为1（CA/MN=1）时，经过不同温度的热处理（700℃，800℃，900℃），所得样品除了主相DyFeO3外，还存在着Dy2O3杂质相。而当CA/MN=1.5时，经过800℃，2h的热处理，就可以得到完全纯相的DyFeO3，这说明当CA/MN=1.5时，更利于DyFeO3相的形成。在CA/MN=1.5的条件下，采用相同的制备工艺，合成了一系列Dy1-xYxFeO3（x=0.1，0.2）纳米粉体。当x=0.1时，经过800℃，900℃，1000℃煅烧，样品中含有极少量的Dy2O3杂质相。对于x=0.2时，经过800℃，900℃，1000℃煅烧，全部都为纯正交钙钛矿DyFeO3相。DyFeO3的室温磁滞回线显示，在低磁场下，显示出铁磁性，而在高磁场下，现出显著的反铁磁特性。
毕业论文关键词： DyFeO3；磁性；掺杂
Abstract
Perovskite-type ReFeO3 (Re=rare earth) constitute a very important class of materials due to their ferromagnetism and magneto-optic effects. They have potential for various applications such as fuel cells, catalysts, gas sensors, semiconductors and magneto-optic materials. Our work on its preparation and magnetic property study will be beneficial for its application in practice in future.
In this experiment, a series of DyFeO3 nano powders with orthorhombic perovskite structure were prepared by sol-gel combustion method. When the ratio of citric acid and metal nitrates for 1 (CA/MN=1), the main phase of DyFeO3 was obtained at different temperatures (700℃ and 800℃ and 900℃), with additional Dy2O3 impurity phases. When CA/MN=1.5, pure phase DyFeO3 was obtained at 800℃, which indicates that DyFeO3 phase is more easily formed when CA/MN=1.5. Under the condition of CA/MN=1.5, a series of Dy1-xYxFeO3 (x=0.1, 0.2) nanoparticles were synthesized by the same preparation process. For Dy1-xYxFeO3（x=0.1),  after calcined at 800℃ 900℃ 1000℃, the sample contained a very small amount of Dy2O3 impurity phase. For x=0.2, all the samples are pure phase Dy1-xYxFeO3, when calcined at 800℃, 900℃, 1000℃. At room temperature, obvious hysteresis loop was observed for DyFeO3. It shows show the ferromagnetism at lower magnetic field, and it bocomes  antiferromagnetic behavior at higher magnetic field.
KeyWords: DyFeO3; Magnetic propery; Doping
目 录
1 文献综述    1
1.1 前言    1
1.1.1ReFeO3概述    1
1.1.2 DyFeO3的结构    1
1.2 DyFeO3的性能    2
1.2.1 DyFeO3的磁性与铁电性能    2
1.2.2 DyFeO3的气敏性能    3
1.3 DyFeO3的应用    4
1.3.1 DyFeO3在磁光器件中的应用    4
1.3.2 DyFeO3在微波器件中的应用    5
1.3.3 DyFeO3在气敏器件中的应用    5
1.4 DyFeO3的制备方法    5
1.4.1 水热法制备DyFeO3    5
1.4.2 溶胶凝胶法合成纳米DyFeO3    6
1.4.3 室温固相反应法制备DyFeO3纳米粉体    7
1.5 选题的目的及意义    7
1.6研究内容与目标    7
1.6.1研究内容    7
1.6.2研究目标    7
2 实验部分    8
2.1 溶胶-凝胶自燃烧法介绍    8
2.1.1 基本原理    8
2.1.2 溶胶-凝胶自燃烧法的影响因素    8
2.1.2反应配比的理论计算    10 稀土掺杂DyFeO3的制备与性能研究+文献综述:http://www.751com.cn/cailiao/lunwen_22429.html