温度制度对BaTiO_3的制备及其电磁性能的影响

Effect of temperature on the synthesis and electromagnetic properties of BaTiO_3

采用溶胶-凝胶法制备四方相纳米BaTiO_3粉末。利用XRD、SEM、矢量网络分析仪等手段对不同温度制度下试样的相结构、形貌、电磁参数进行了表征,并通过电磁参数采用MATLAB编程计算得出试样在2~18GHz范围内反射率随频率的变化曲线。实验结果表明,随热处理温度的提高,BaTiO_3中四方相含量先增加后减少,且其晶粒粒径逐渐长大;当热处理温度为1 000℃时,试样具有最优的介电损耗性能,并采用MATLAB编程计算得出其反射率能够优于-10dB的带宽达3.8GHz,最小反射率出现在14GHz,峰值为-25.13dB。

Tetragonal BaTiO_3 nano powders have been synthesized via sol-gel process in this paper.The phase structure,morphology and electromagnetic parameters of the BaTiO_3 nanometer powders were investigated by X-ray diffraction（XRD）,scanning electron microscope（SEM）and vector network analyzer at different heat treatment temperatures.Moreover,the MATLAB programming was applied to calculate the electromagnetic parameters and obtain the changing curve of reflectivity with the variation of frequency in the range of 2-18 GHz.It was found that the content of tetragonal BaTiO_3 would be first increased and then decreased with the increment of the heat treatment temperature and the size of grains increased gradually.When the heat treatment temperature reached 1 000 ℃,the sample exhibited the best dielectric loss properties.Then,MATLAB programming was used to calculate the reflectivity,whose bandwidth over -10 dB could be up to 3.8GHz.In the meanwhile,the minimum reflectivity appeared at 14 GHz and could reach -25.13 dB.