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钙钛矿铁电材料的性能研究

时间:2019-11-24 20:22来源:毕业论文
采用改进的陶瓷工艺制备 x=0.3 的[KNbO3]1-x[BaNi1/2Nb1/2O3-δ]x (KBNNO)氧化物材料。以K2CO3 ,BaCO3 ,NiO 和Nb2O5为主要原料,原料经球磨、烘干、预烧、粉碎、成型、排塑、烧结和退火

摘要[KNbO3]1-X[BaNi1/2Nb1/2O3-δ]X(KBNNO)氧化物材料是具有铁电性质的钙钛矿铁电材料,还表现出了变化范围在1.1eV-3.8eV的直接带隙,通过调节Ni+的含量能够使它的能带隙位于可见光范围内。KBNNO 氧化物材料在带隙的可调性和磁变化显示出了潜在性,使其在太阳能光伏材料和多铁的应用上有着巨大的潜力。经过实验表明 x=0.3 时的[KNbO3]1-x [BaNi1/2 Nb1/2O3-δ]x(KBNNO)氧化物材料相比于其他组分比的性能要好,因此我们把该组分比的氧化物作为本次的实验对象。 本课题采用改进的陶瓷工艺制备 x=0.3 的[KNbO3]1-x[BaNi1/2Nb1/2O3-δ]x (KBNNO)氧化物材料。以K2CO3  ,BaCO3  ,NiO 和Nb2O5为主要原料,原料经球磨、烘干、预烧、粉碎、成型、排塑、烧结和退火等一系列加工工艺得到陶瓷样品。在实验过程中探索和制定合理的工艺参数。陶瓷样品经XDR、SEM等分析手段,分析陶瓷在不同烧结温度下的结晶性能、晶格常数、晶相及晶粒大小形状等显微结构。 通过对实验结果的分析和讨论,我们得出了以下几点主要结论: (1)所有的样品XRD 图均符合纯铌酸钾的标准图谱,表现出了单一的钙钛矿结构;并且随着烧结温度的增加,晶胞参数和晶面间距变小; (2)随着温度从 1060℃升高到 1090℃,高温烧结过程中提供了充足的形核动力,使晶粒尺寸增大,直径能够到达 2μm左右,样品表面的致密度越来越高,空位越来越少,烧结出的样品性能也逐渐提高; (3)在无外加电场下,样品的介电常数都随频率升高在逐渐降低,但就某一频率下比较,如在 100kHz 下,样品的介电常数从 195V/m 增加到 388V/m,温度升高使介电常数增大; (4)陶瓷样品的剩余极化强度 Pr 随着温度的升高从0.8 uC/cm2增长到 3.9uC/cm2,矫顽场从32.6 kV/cm到 63.2kV/cm呈递增状态,样品的铁电性能在增强。   42032
毕业论文关键词:  铁电材料  钙钛矿型   KBNNO氧化物   陶瓷
Title   Study on properties of Perovskite Ferroelectric Materials   
Abstract [KNbO3]1-x[BaNi1/2Nb1/2O3-δ]x(KBNNO) oxide materials are ferroelectric materials with ferroelectric properties, and also show a direct band gap of 1.1eV-3.8eV, which can be located in the range of visible light by adjusting the content of Ni+. Experiments show that when x=0.3 [KNbO3]1-x[BaNi1/2Nb1/2O3-δ]x(KBNNO) oxide material is better than other components. We prepared [KNbO3]1-x[BaNi1/2Nb1/2O3-δ]X(KBNNO) oxide materials by improved ceramic technology in this paper.  The crystal properties, lattice constant, crystal phase, grain size and shape of the ceramics were analyzed by means of XDR and SEM analysis. Through the analysis and discussion of the experimental results, we draw the following main conclusions:  (1) All the XRD diagram are in line with the standard spectrum of pure potassium showed a single perovskite structure; (2) With the temperature rising from 1060 ℃to 1090 ℃, diameter can reach about 2 μm, the sample surface by density becomes higher and higher; (3)  Without external electric field, such as at 100kHz, the dielectric permittivity of the samples from the 195V/m increased to 388V/m, the dielectric constant increases with the increasing of temperature; (4) The remnant polarization strength of ceramic samples increased from 0.8uC/cm2 to 3.9uC/cm2 with the increase of temperature, the coercive field from 32.6kV/cm to 63.2kV/cm showed an increasing state.   Keywords    Ferroelectric material  ,   Perovskite type ,   KBNNO oxide ,       ceramics

目次

1引言1

1.1铁电材料的物理性质1

1.2铁电材料的研究现状3

1.2.1钙钛矿太阳能电池的光伏特性3

1.2.2目前研究中的主要体系4 钙钛矿铁电材料的性能研究:http://www.lwfree.com/cailiao/lunwen_42303.html

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