液相包覆法引入B_2O_3对Ba_2Ti_9O_(20)陶瓷介电性能的影响

Effects of adding B_2O_3 by liquid phase coating process on the dielectric properties of Ba_2Ti_9O_(20) ceramics

以BaCO3和TiO2粉末为原料,采用固相反应法合成Ba2Ti9O20主晶相,以H3BO3溶液为前驱液,通过液相包覆技术引入B2O3助烧剂以降低Ba2Ti9O20陶瓷的烧结温度。研究了液相包覆B2O3对Ba2Ti9O20陶瓷的烧结和介电性能的影响。结果表明,液相包覆B2O3后,Ba2Ti9O20陶瓷的烧结温度从1 400℃降至1 250℃,相对密度达98.3%。当H3BO3溶液的浓度为1.0 mol/L,1 250℃烧结4 h所制Ba2Ti9O20陶瓷的介电性能良好:相对介电常数εr=42,介质损耗tanδ=0.002,频率温度系数τf=–4×10–6/℃(1 MHz)。

Ba2Ti9020 main phase was prepared using BaCO3 and TiO2 powders as raw materials by solid state reaction method. In order to reduce the sintering temperature of Ba2TigO20 ceramic, liquid phase coating process was used to dope B203 using H3BO3 solution as precusor. The effects of B203 doping on the sintering and dielectric properties of Ba2Ti9020 ceramic were studied. The results show that liquid phase coating with B203 could decrease the sintering temperature of Ba2Ti9020 ceramic from 1 400 ℃ to 1 250℃. When the concentration of H3BO3 sulotion is 1.0 mol/L, a high relative density of 98.3% and good dielectric properties of εr=42, tanδ= 0.002 （ 1 MHz）, τf=-4×10^-6/℃（1MHz）. are obtained for the Ba2TigO20 ceramic sintered at 1 250℃for 4 h.