二氧化钛基高介电陶瓷的制备及物性研究
发布时间：2018-12-18 12:57
【摘要】：高介电材料是电容器、存储器、谐振器、滤波器等重要电子器件向高性能化和尺寸微型化进一步发展的重要基础。由于器件小型化和高能量密度存储的应用需要,对高介电材料的探索是近年国内外新材料研究领域的一个热点。然而,在单一材料中同时实现高介电性、低损耗、工作频带宽、温度稳定和可耐强电场的优异综合介电性能仍然是一项极其具有挑战性的任务。在此背景下,本论文主要开展了(In, Nb)掺杂Ti02高介电陶瓷材料的制备、物性及相关机理的研究。Ti02陶瓷作为研究最早的介电材料,具有较高的相对介电常数、低的介电损耗、低的电导率以及非常高的抗击穿电场强度。因此,Ti02基陶瓷材料对于高储能密度电容器的应用是一类具有非常重要的研究价值和意义的介质材料。近期,澳大利亚国立大学的研究组报道了(In, Nb)共掺杂TiO2等组分陶瓷具有良好的高介电性质,该研究组在低于实验测量频率1 MHz的范围内同时实现了介电常数δ≥104、介电损耗tanδ≤0.05的性能,并且在80K至450K很宽的温度范围内呈现出不怎么依存温度和频率的高介电常数和低的介电损耗。我们知道纯TiO2的介电常数只有120左右,而进行了(In, Nb)掺杂改性后介电常数提高到104,并且损耗保持在0.05以下,这极大的提高了TiO2的介电性能。虽然(In, Nb)掺杂后陶瓷呈现出如此高介电常数的物理机制尚存在一定争议,但这一成果的发现对研究具有优异介电性能的材料提供了一条新的途径。本论文研究了利用传统固相反应法制备的(In, Nb)掺杂Ti02陶瓷样品。考察了不同组分掺杂的陶瓷介电性质以及烧结工艺、球磨时间对其介电性质的影响,并初步探索了陶瓷的高介电性质的物理机制。一、利用固相反应法制备了一系列不同烧结温度条件的(In, Nb)掺杂Ti02陶瓷样品,系统地考察了它们的晶体结构、微观组织结构、介电频谱和复阻抗频谱的电学性质及其随测试温度的变化。首先利用普通烧结制备的陶瓷样品的介电常数随掺杂组分、烧结温度、保温时间都有一定规律性的变化,并且都具有极高的介电常数。但这种方法制备的样品重复性较差,大部分陶瓷样品的介电损耗低频和高频都在10%以上,只有中频段损耗较低。为了能保证高介电常数的同时降低样品的损耗,我们利用等静压成型烧结制备样品,在通过热处理后其介电性能得到了很大改善,尤其在800℃C退火样品的介电性能最好。其介电常数在10 mHz～10 MHz都稳定保持在104以上,并且介电损耗在很宽的频率范围内都小于5%,另外随测试温度的变化其介电常数也基本不变,显示了良好的温度稳定性。综合来说,通过等静压成型烧结后退火处理的样品各方面的介电性能都非常优异。二、研究了一些(In, Nb)掺杂TiO2陶瓷呈现高介电常数的影响因素,对其高介电性起源的物理机制进行初步探究。通过不等比例掺杂实验,发现过量的In和Nb都会对陶瓷的介电性能产生影响,过量掺杂In会使陶瓷的介电常数和介电损耗降低,而过量的Nb会使陶瓷介电常数和损耗增大。作者推测只有In和Nb等比例掺杂才会出现高介电常数低损耗的陶瓷样品。通过表面处理实验,发现进行表面处理后的样品,介电常数急剧增大了一个数量级,再经过退火后陶瓷的介电常数又恢复到较低的数值,可以推测陶瓷的介电常数与表面氧化层的氧化程度有关。三、探讨了不同球磨时间对陶瓷介电性能的影响。通过分析球磨前后粉料的SEM图片看出球磨时间延长粉料分散的更均匀,XRD图谱也显示没有混入大量Zr02杂质。对于球磨30 h的粉料,在不同烧结温度样品的介电频谱测试发现,其最佳烧结温度为1400℃,另外测试了样品变温的介电频谱和阻抗谱显示了其介电性能在测试温度范围内介电性能比较稳定,这也是(In, Nb)掺杂Ti02这类陶瓷共有的一个规律。
[Abstract]:High dielectric material is an important base for the further development of high-performance and small-scale miniaturization of important electronic devices such as capacitors, memory, resonators, filters and the like. Due to the need of device miniaturization and high energy density storage, the exploration of high dielectric materials is a hot spot in the field of new material research in recent years. However, the excellent comprehensive dielectric properties of high dielectric, low loss, wide working band, temperature stability and strong electric field are still an extremely challenging task in a single material. In this paper, the preparation, physical properties and related mechanism of (In, Nb) doped Ti02 high dielectric ceramic materials are studied. As the earliest dielectric material, Ti02 ceramics have high relative dielectric constant, low dielectric loss, low electrical conductivity and very high resistance to electric field strength. Therefore, the application of Ti02-based ceramic materials to high-energy-storage-density capacitors is a kind of medium material with very important research value and significance. Recently, the study group of the Australian National University has reported that (In, Nb) co-doped TiO2 and other component ceramics have good dielectric properties, and the study group has realized the performance of the dielectric constant, the dielectric constant, the dielectric constant, the dielectric loss tan and the dielectric constant of 0.05 in the range below the experimental measurement frequency of 1 MHz. and exhibit a high dielectric constant and a low dielectric loss that are less dependent on temperature and frequency over a wide temperature range of 80k to 450k. We know that the dielectric constant of the pure TiO2 is about 120, and the dielectric constant is increased to 104 after (In, Nb) doping modification, and the loss is kept below 0.05, which greatly improves the dielectric property of the TiO2. Although (In, Nb) doped ceramic exhibits such a high dielectric constant, the physical mechanism is still controversial, but the discovery of this result provides a new way for the study of materials with excellent dielectric properties. In this paper, the (In, Nb) doped Ti02 ceramic samples prepared by the conventional solid-phase reaction method are studied. The influence of different component-doped ceramic dielectric properties as well as the sintering process and ball-milling time on the dielectric properties of the ceramics was investigated, and the physical mechanism of the high dielectric properties of the ceramics was preliminarily explored. In this paper, a series of (In, Nb) doped Ti02 ceramic samples with different sintering temperature conditions were prepared by solid-phase reaction, and their crystal structure, microstructure, dielectric and complex impedance spectra were systematically investigated. firstly, the dielectric constant of the ceramic sample prepared by ordinary sintering has a certain regular change with the doping component, the sintering temperature and the heat preservation time, and the ceramic sample has a very high dielectric constant. but the repeatability of the samples prepared by the method is poor, and the dielectric loss and the high frequency of a large part of the ceramic samples are more than 10%, and only the middle frequency band is low in loss. In order to ensure the high dielectric constant, the loss of the sample can be reduced, and the sample is prepared by isostatic pressing and sintering, and the dielectric property of the sample is greatly improved after the heat treatment, and the dielectric property of the sample is best in particular at the temperature of 800 DEG C. the dielectric constant is stable at 10mHz-10MHz, and the dielectric loss is less than 5% in a wide frequency range, and the dielectric constant of the dielectric constant is basically unchanged with the change of the test temperature, and good temperature stability is displayed. In general, the dielectric properties of each aspect of the sample treated by isostatic pressing are excellent. In this paper, the influence factors of high dielectric constant of (In, Nb) doped TiO2 ceramics are studied, and the physical mechanism of high dielectric constant of the (In, Nb) doped TiO2 ceramics is studied. In addition, the dielectric constant and dielectric loss of the ceramic can be reduced by the overdoping of In, and the dielectric constant and the loss of the ceramic can be increased. The authors speculate that only in-and-Nb-ratio doping results in high dielectric constant low-loss ceramic samples. The surface treatment experiment shows that the dielectric constant of the sample after surface treatment is increased by an order of magnitude, and the dielectric constant of the ceramic is restored to a lower value after the annealing, and the dielectric constant of the ceramic can be presumed to be related to the degree of oxidation of the surface oxide layer. The effect of different ball milling time on the dielectric properties of the ceramic was discussed. Through the analysis of the SEM pictures of the powder before and after the ball milling, it can be seen that the grinding time of the ball is more uniform than that of the powder, and the XRD pattern also shows that no large amount of the Zr02 impurity is mixed. For the powder of the ball mill for 30 h, the optimum sintering temperature is 1400 鈩，
本文编号：2385883
[Abstract]:High dielectric material is an important base for the further development of high-performance and small-scale miniaturization of important electronic devices such as capacitors, memory, resonators, filters and the like. Due to the need of device miniaturization and high energy density storage, the exploration of high dielectric materials is a hot spot in the field of new material research in recent years. However, the excellent comprehensive dielectric properties of high dielectric, low loss, wide working band, temperature stability and strong electric field are still an extremely challenging task in a single material. In this paper, the preparation, physical properties and related mechanism of (In, Nb) doped Ti02 high dielectric ceramic materials are studied. As the earliest dielectric material, Ti02 ceramics have high relative dielectric constant, low dielectric loss, low electrical conductivity and very high resistance to electric field strength. Therefore, the application of Ti02-based ceramic materials to high-energy-storage-density capacitors is a kind of medium material with very important research value and significance. Recently, the study group of the Australian National University has reported that (In, Nb) co-doped TiO2 and other component ceramics have good dielectric properties, and the study group has realized the performance of the dielectric constant, the dielectric constant, the dielectric constant, the dielectric loss tan and the dielectric constant of 0.05 in the range below the experimental measurement frequency of 1 MHz. and exhibit a high dielectric constant and a low dielectric loss that are less dependent on temperature and frequency over a wide temperature range of 80k to 450k. We know that the dielectric constant of the pure TiO2 is about 120, and the dielectric constant is increased to 104 after (In, Nb) doping modification, and the loss is kept below 0.05, which greatly improves the dielectric property of the TiO2. Although (In, Nb) doped ceramic exhibits such a high dielectric constant, the physical mechanism is still controversial, but the discovery of this result provides a new way for the study of materials with excellent dielectric properties. In this paper, the (In, Nb) doped Ti02 ceramic samples prepared by the conventional solid-phase reaction method are studied. The influence of different component-doped ceramic dielectric properties as well as the sintering process and ball-milling time on the dielectric properties of the ceramics was investigated, and the physical mechanism of the high dielectric properties of the ceramics was preliminarily explored. In this paper, a series of (In, Nb) doped Ti02 ceramic samples with different sintering temperature conditions were prepared by solid-phase reaction, and their crystal structure, microstructure, dielectric and complex impedance spectra were systematically investigated. firstly, the dielectric constant of the ceramic sample prepared by ordinary sintering has a certain regular change with the doping component, the sintering temperature and the heat preservation time, and the ceramic sample has a very high dielectric constant. but the repeatability of the samples prepared by the method is poor, and the dielectric loss and the high frequency of a large part of the ceramic samples are more than 10%, and only the middle frequency band is low in loss. In order to ensure the high dielectric constant, the loss of the sample can be reduced, and the sample is prepared by isostatic pressing and sintering, and the dielectric property of the sample is greatly improved after the heat treatment, and the dielectric property of the sample is best in particular at the temperature of 800 DEG C. the dielectric constant is stable at 10mHz-10MHz, and the dielectric loss is less than 5% in a wide frequency range, and the dielectric constant of the dielectric constant is basically unchanged with the change of the test temperature, and good temperature stability is displayed. In general, the dielectric properties of each aspect of the sample treated by isostatic pressing are excellent. In this paper, the influence factors of high dielectric constant of (In, Nb) doped TiO2 ceramics are studied, and the physical mechanism of high dielectric constant of the (In, Nb) doped TiO2 ceramics is studied. In addition, the dielectric constant and dielectric loss of the ceramic can be reduced by the overdoping of In, and the dielectric constant and the loss of the ceramic can be increased. The authors speculate that only in-and-Nb-ratio doping results in high dielectric constant low-loss ceramic samples. The surface treatment experiment shows that the dielectric constant of the sample after surface treatment is increased by an order of magnitude, and the dielectric constant of the ceramic is restored to a lower value after the annealing, and the dielectric constant of the ceramic can be presumed to be related to the degree of oxidation of the surface oxide layer. The effect of different ball milling time on the dielectric properties of the ceramic was discussed. Through the analysis of the SEM pictures of the powder before and after the ball milling, it can be seen that the grinding time of the ball is more uniform than that of the powder, and the XRD pattern also shows that no large amount of the Zr02 impurity is mixed. For the powder of the ball mill for 30 h, the optimum sintering temperature is 1400 鈩，
本文编号：2385883
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