0.7CaTiO_3-0.3(La_xNd_(1–x))AlO_3微波介质陶瓷的研究

Study on 0.7CaTiO_3-0.3(La_xNd_(1–x))AlO_3 microwave dielectric ceramics

利用传统固相反应法制备了具有不同LaAlO3含量的0.7CaTiO3-0.3(LaxNd1–x)AlO3(以下简称CTLNA)系微波介质陶瓷,研究了所制CTLNA陶瓷的微观结构和微波介电性能。结果表明,用x=0.5的La3+取代Nd3+能有效促进样品晶粒的均匀分布,降低样品的气孔率。少量添加SrTiO3能进一步增加样品的致密度,提高CTLNA系微波陶瓷的介电性能。经原料组分及工艺优化,制备的0.7(Sr0.01Ca0.99)TiO3-0.3(La0.5Nd0.5)AlO3样品密度高、晶相均匀,其微波介电性能如下:εr=45.87,Q.f=41 612 GHz(4 GHz),τf=10×10–6/℃。

0.7CaTiO3-0.3（LaxNd（1-x））AlO3（CTLNA） ceramics with different contents of LaAlO3 were prepared by traditional solid state sintering. Mierostructure and microwave dielectric properties of the prepared CTLNA ceramics were studied. The results show that the Nd2＋ amount to x=0.5 which is substituted by La2＋ overcomes the difficulty of getting compact ceramics. The influence of SrTiO3 on the sintering characters, dielectric properties and microstructure of CTLNA ceramics was also discussed. A little addition of SrTiO3 promotes the growth of the crystal grain, reduces the porosity of samples and improve the dielectric properties of the CTLNA ceramics. After optimization of raw material composition and preparation process, the prepared 0.7（Sr0.01Ca0.99）TiO3-0.3（La0.5Nd0.5）AlO3 samples show high density and a uniform grain structure with er45.87, Q ·f=41 612 （at4 GHz）, τf=10×10^-6/℃.