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摘要：钙钛矿稀土锰氧化物AMnO3（A代表稀土）是一类重要的多功能材料，具有诸多优良性质，譬如其具有铁磁性、磁光性，特别是它表现出特别明显的磁电阻效应等物理特征，是当下材料学界和物理学界十分有研究前景的领域。本次实验所研究的ErMnO3是一种六方结构的锰氧化物，被证明是具有铁电反铁磁性的多铁性材料。51107
本实验采用溶胶凝胶法制备一系列钙钛矿结构的Cr掺杂ErMnO3粉体。样品制成后利用XRD、TEM、VSM等检测方法，详细研究了Cr掺杂对于ErMnO3的结构、形貌和磁性能的影响规律。当CA/MN=1:1的时候，热处理温度达到1000℃的时候可以得到纯相ErMnO3，但在CA/MN=1:1.5时，有一定强度的Er2O3杂相。热处理温度在800℃和900℃的时候，除了ErMnO3的相之外，均有不同强度的Er2O3杂相。采用相同的实验步骤，还制备了一系列的Cr掺杂实验，即ErMn1-xCrxO3（x=0.05,0.1,0.2）。当x=0.05时，热处理温度达到1000℃时，得到接近纯相的样品；当x=0.1时，热处理温度达到1100℃时，存在Er2O3和MnO2杂相；当x=0.2时，热处理温度达到1100℃时，存在杂相MnO2、Er2O3和Mn2O7。在室温下，ErMnO3的M-H曲线都是完整的线性直线，它的磁化率随着磁场强度的增加而成线性增长，表现出典型顺磁性。在x=0.05的掺杂情况下，对该体系磁性的调控作用不明显。粉体有团聚现象，颗粒大概在200~400nm之间。
毕业论文关键词：钙钛矿型化合物；ErMnO3；磁性能；溶胶凝胶法；掺杂
Synthesis and magnetic properties of ErMnO3 powders
Abstract:AMnO3 perovskite compounds on behalf of rare earth (A=rare earth) is a kind of important material, has a ferromagnetic, magnetic fine properties such as light, and the rare earth is one kind of manganese oxide has many special properties and broad prospects for using the compounds. In this experiment, we use sol-gel method to prepare ErMnO3 and ErMn1-xCrxO3 powders.
In this experiment, by optimizing process, a series of Cr doped ErMnO3 powders, with perovskite structure, were prepared by sol-gel self-propagating combustion method. Combined with XRD,TEM,VSM, the structure, morphology and magnetic properties of Cr doped ErMnO3 were systematically investigated. When the CA/MN = 1 , pure phase ErMnO3 was obtained when heat treatment temperature is 1000℃. When the CA/MN=1.5, pure phase ErMnO3 was obtained when heat treatment temperature is 1100℃.Using the same process conditions, the preparation of a series of Cr doped preparation ErMn1 - xCrxO3 (x = 0.05, 0.1, 0.2) was conducted. When x = 0.05, calcined at 800℃, 900℃, the samples containes ErMnO3 main crystal phase, and also Er2O3 mixed phase. Pure phase ErMnO3 was obtained when heat treatment temperature is 1000℃. When the x = 0.1, the samples containes ErMnO3 main crystal phase, and also Er2O3 and MnO2 mixed phase. When the x=0.2, calcined at 1100℃, Pure phase ErMnO3 was not obtained, Er2O3,Mn2O7 and MnO2 mixed phase. At room temperature, M-H curve OF ErMnO3 is a complete linear straight line, and it increased with the increase of the intensity of magnetic field of magnetic susceptibility to linear growth. It shows the typical paramagnetic behavior. Under the condition of doping of x = 0.05, the system of magnetic control effect is not obvious.
Keywords：Perovskite oxide;ErMnO3; Magnetism;Sol-gel method;Dope
目 录
1.1 前言 1
1.2 稀土锰氧化物简介 1
1.2.1 稀土锰氧化物 1
1.2.2 稀土锰氧化物的结构特征 2
1.2.3 稀土锰氧化物的磁学特性 4
1.3 稀土锰氧化物的多铁特性