《层状钙钛矿多铁材料Bi6FeCrTi3O18陶瓷制备及性能研究》-毕业论文.doc

PAGE 层状钙钛矿多铁材料 Bi6FeCrTi3O18陶瓷制备及性能研究 微电子系 摘要： 通过氧化物Bi2O3, TiO2, Fe2O3 Cr2O3为原料，采用传统固相烧结工艺制备五层钙钛矿多铁材料Bi6FeCrTi3O18(BFCrT)陶瓷。通过对样品在不同的烧结温度和时间下的微观结构的分析和相关物理性能的测量，研究了样品制备条件和组份对样品的影响。通过XRD谱的分析，我们发现在合适的烧结条件下，用固相烧结工艺可以制备出单相五层钙钛矿结构的BFCrT陶瓷。通过扫描电镜对样品晶粒形貌进行观察，BFCrT陶瓷的晶体形貌为片状，并且形状较为一致，而烧结条件影响了样品的致密度。从样品的铁电性能测量结果可以看出，样品在烧结过程中Bi的多少对样品的铁电性能影响较大，随着烧结过程中Bi的挥发，样品的漏电流明显增大。另外，在室温下用VSM磁性测量仪测量样品的铁磁性，样品都具有弱磁性，并且Bi含量还对磁性产生影响。 关键词：钙钛矿；陶瓷；多铁性；铁电；铁磁 Preparation and multiferroic properties of Bi6FeCrTi3O18 samples Abstract: Adopt traditional solid-phase sintering process to prepare Bi6FeCrTi3O18 ceramics which is multiferroic samples of bismuth layer perovskite with metal oxide. Use X-ray diffraction (XRD) to measure, the XRD spectra of samples under different conditions to analysis the micro-structure the of the samples and from the XRD measurement we can see that when under appropriate sintering conditions, we can prepare single-phase Bi6FeCrTi3O18 ceramics of 5 layers-perovskite structure. Observe the Cross-section of the samples by scanning electron microscopy (SEM) observation and the SEM results show that the morphology of the crystalline of the sample is of piease structure and the shape is comparatively consistent. At room temperature (RT), the ferroelectric of the sample was measured，we find that the content of Bi has a great influence to ferroelectrics. With the volatilization of Bi during the sintering process，the leaking current of the sample is increasing. The magnetic properties were measured by vibrating sample magnetometer (VSM), the samples was the magnetic properties at RT. Keywords：Layer-perovskite; Ceramic；Multiferroics; Ferroelectrics; Ferromagnetic 目录 一、 绪论 (一) 铁电性·························································································································5 1.1.铁电材料·························································································································5 1.2.电滞回线·································