纳米晶钛酸钡基材料的制备、性能及应用
发布时间：2018-11-14 08:36
【摘要】：本论文围绕纳米晶钛酸钡颗粒材料的研究展开,独创了“一步溶胶法”,在低温下制备出了晶粒尺寸小于10nm的一系列高结晶度钛酸钡粉体及颗粒薄膜,系统地对10nm以内小尺寸钛酸钡的相结构及物理性能展开了研究,探讨了钛酸钡维持铁电性的极限尺寸,并成功地将其应用在储能薄膜和镍粉包覆技术,实现了钛酸钡纳米晶颗粒材料的有效应用。通过对钛酯水解-交联反应速率的精准控制,独创了介于溶胶凝胶法和沉淀法之间的“一步溶胶法”,常压下制备出了平均晶粒尺寸小至2.8nm的结晶型钛酸钡颗粒及其稳定溶胶。该方法成功地应用于方形钛酸锶纳米晶及其稳定溶胶的制备。采用该稳定溶胶在160℃的低温下制备出了高结晶度的钛酸盐颗粒薄膜。利用拉曼、同步辐射衍射、成对分布函数(PDF)和X射线光电子能谱(XPS)分析发现小至2.8nm的钛酸钡颗粒呈现多相共存的结构特征,非中心对称相含量与颗粒表面结构密切相关。其相变过程十分弥散,分布在较宽的温度范围内,且非中心对称的四方、正交相结构在400℃的高温下依然存在,首次证实了小至2.8nm的钛酸钡颗粒依然具有铁电性。对纳米晶钛酸钡颗粒进行了一系列的物理性能分析表征。二次谐波产生(SHG)实验证实了这些纳米晶颗粒在室温下具有非线性极化效应,并且SHG响应随温度的升高逐渐下降,呈现出由非中心对称的铁电相结构逐渐向顺电相转变的趋势。颗粒在外加电场下的极化翻转行为和介电性能测试均进一步证实了小至2.8nm的钛酸钡颗粒具有铁电性。最后本文对这些纳米晶颗粒在多方面的应用进行了探索。利用获得的稳定溶胶在≤160℃的低温下制得了高结晶度的钛酸盐颗粒薄膜,薄膜呈现良好的介电特性和温度稳定性;通过多层化结构设计,具有铁电性的8nm钛酸钡颗粒在有机-无机复合材料中获得了高的电位移极化,有效地实现了复合薄膜的高击穿场强(495kV/mm)和高储能密度(19.37J/cm3);将纳米晶钛酸钡材料的制备方法应用于镍粉表面的包覆改性,通过快速高效的一步反应形成了致密均匀的钛酸钡多晶包覆层,有效延缓了纳米镍粉的烧结收缩并改善了其抗氧化性能。
[Abstract]:In this paper, a series of high crystallinity barium titanate powders and granular films with grain size smaller than 10nm were prepared at low temperature by "one-step sol method", focusing on the research of nanocrystalline barium titanate particles. The phase structure and physical properties of small size barium titanate in 10nm are systematically studied. The limiting size of barium titanate to maintain ferroelectric properties is discussed, and successfully applied to the coating technology of energy storage film and nickel powder. The effective application of nanocrystalline barium titanate material has been realized. By precisely controlling the rate of hydrolysis and crosslinking of titanium esters, a one-step sol method was created between sol-gel method and precipitation method. Crystallized barium titanate particles with average grain size as small as 2.8nm and their stable sol were prepared under atmospheric pressure. The method has been successfully applied to the preparation of cubic strontium titanate nanocrystalline and its stable sol. Titanate granular films with high crystallinity were prepared by using the stable sol at low temperature of 160 鈩，
本文编号：2330672
[Abstract]:In this paper, a series of high crystallinity barium titanate powders and granular films with grain size smaller than 10nm were prepared at low temperature by "one-step sol method", focusing on the research of nanocrystalline barium titanate particles. The phase structure and physical properties of small size barium titanate in 10nm are systematically studied. The limiting size of barium titanate to maintain ferroelectric properties is discussed, and successfully applied to the coating technology of energy storage film and nickel powder. The effective application of nanocrystalline barium titanate material has been realized. By precisely controlling the rate of hydrolysis and crosslinking of titanium esters, a one-step sol method was created between sol-gel method and precipitation method. Crystallized barium titanate particles with average grain size as small as 2.8nm and their stable sol were prepared under atmospheric pressure. The method has been successfully applied to the preparation of cubic strontium titanate nanocrystalline and its stable sol. Titanate granular films with high crystallinity were prepared by using the stable sol at low temperature of 160 鈩，
本文编号：2330672
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