高性能BaTiO_3基PTCR陶瓷的制备与表征

Preparation and Characterization on BaTiO_3-based PTCR Ceramics with High Performance

以乙酸钡和钛酸四丁酯为主要原料，采用溶胶-凝胶（sol-gel）法制备了BaTiO3基PTCR纳米晶粉体。通过热分析（TG-DSC）、X射线衍射（XRD）分析了粉体的合成过程和晶粒尺寸及相结构；纳米晶粉体经造粒、成型、烧结获得了居里温度（TC）为100℃，室温电阻率（p25℃）～18Ω·cm，温度系数（α30）～17％·℃^-1，耐电压（Vb）〉195V·mm^-1，电阻率突变（pmax/pmin）〉10^6的PTC陶瓷材料，并通过扫描电子显微镜（SEM）对其显微结构进行了观察。

The nanocrystalline BaTiO3-based PTCR powder had been prepared by sol-gel method, using Ba（Ac）2 and Ti（OC4H9 ）4 as the principle starting materials. The thermal decomposition behavior, crystallite size and structural development of the powder were analyzed by using TG-DSC and XRD. The nanocrystalline powder was pressed into pellets, followed by sintering to yield PTCR ceramic material, which had a Curie temperature （To） of 100℃, a resistivity at room temperature （p25℃） of - 18Ω·cm, a temperature coefficient of resistivity （α30） of - 17 % · ℃^-1, a withstand voltage intensity（Vb ） of 〉 195V· mm^-1 and a resistivity step ratio （pmax/pmin） of 〉 106. The morphology of PTCR ceramic material was studied by using SEM.