CaCu3Ti4O12 voltage-sensitive ceramic with high potential gradient and low dielectric loss and preparation method thereof

Abstract

The invention relates to a CaCu3Ti4O12 voltage-sensitive ceramic with high potential gradient and low dielectric loss and a preparation method thereof. The method comprises the following steps: mixingCaCO3, CuO, TiO2, ZnO and Al2O3 according to a molar ratio of 1:3:4:(0-5%):(0-5%); carrying out wet ball milling for 12h, drying mixed powder at 80 DEG C for 12h; putting the mixture into a graphitemold and placing the mold in a discharge plasma sintering furnace for sintering at 750 DEG C for 10min; and placing a sintered sample in a muffle furnace for annealing at 1000 DEG C for 3 hours, and then naturally cooling the sample to obtain a target voltage-sensitive ceramic. The method adopts a discharge plasma sintering technology to prepare the voltage-sensitive ceramic, the sintering temperature and the heat preservation time are greatly reduced, the method is more energy-saving and more environment-friendly, the potential gradient of the obtained CaCu3Ti4O12 voltage-sensitive ceramic isreaches 1200V / mm or more, and the dielectric loss is reduced to about 0.02 at 1kHz.

Description

technical field [0001] The invention relates to pressure-sensitive ceramics, in particular to a high potential gradient, low dielectric loss CaCu 3 Ti 4 o 12 Pressure-sensitive ceramics and methods for their preparation. Background technique [0002] Varistor ceramics refer to electronic materials that have nonlinear volt-ampere (V-I) characteristics within a certain voltage range, and their resistance value decreases sharply with the increase of voltage. It is a typical electronic material controlled by grain size and grain boundary structure. Electronic functional materials. The improvement of the voltage level of the transmission circuit and the increase of the transmission capacitance put forward higher requirements for the light weight and miniaturization of the overvoltage protection device. At the same time, the growing information technology requires higher integration, high speed and low power consumption. The demand for power electronic devices is also driven t...

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Problems solved by technology

[0003] Traditional CaCu 3 Ti 4 o 12 The formula and preparation process of pressure-sensitive ceramics are complex, including complex processes such as mixing, pre-sintering, sieving, granulation, and debinding. The final sintering temperature is usually at 1050 o C or above, heat preservation for more than 10h, high energy consumption, and CaCu 3 Ti 4 o 12 The potential gradient of varistor ceramics is not high, usually around 200-300V / mm, and the dielectric loss is as high as 0.1-1 order of magnitude, which is difficult to meet the requirements of low loss and miniaturization of current power electronic devices

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