The Study Of Sructure And Dielectric Properties Of BaO-Nd₂O₃-TiO₂ Dielectric Ceramics

The purpose of this paper is to prepare a new high frequency dielectric ceramic that has high permittivity, low dielectric loss, and low temperature coefficient of capacitance. BaO―Nd₂O₃―TiO₂ system is studied in this paper. There are two main types of compound in the system:BaNd₂Ti₅O₁₄ and BaNd₂Ti₃O₁₀. Better properties of dielectric materials are got when close to BaO-Nd₂O₃-5TiO₂ . The pure BaO―Nd₂O₃―TiO₂ system was not solid when sintered. The addictive of Bi₂O₃(10wt%—20wt%) can help improve the properties and accelerate the sintering process.Firstly, this paper studied craftwork of this system. Based on the dielectric performance and microstructure of the system, the best proper sintering temperature and the best proper calcination temperature are as follows: sintering temperature : 1200℃(ascending 3h, holding 3 h) calcination temperature : 1000℃(ascending 1.5h, holding 2 h)The best suit composition is 0.127BaCO₃+0.207 Nd₂O₅+ 0.093Bi₂O₃+0.573TiO₂.XRD indicated that the main crystal phase of the system is BaNd₂Ti₁₅O₁₄ and the vice main crystal phase is Bi₄Ti₃O₁₂ and Nd₂Ti₂O₇。. The dielectric properties of the system are as follows:ε=106.1 (measurement frequency 1MHz) tanδ=2.1×10^-4 (measurement frequency 1MHz)αC = -14.05×10^-6/℃(+25℃～+85℃,measurement frequency 1kHz)...