LMT-CT-LST高介电复合陶瓷的制备及性能调控

发布时间：2018-03-09 17:12

  本文选题：显微结构　切入点：钙钛矿　出处：《压电与声光》2017年05期 　论文类型：期刊论文

【摘要】：采用传统固相合成法制备0.1La(Mg_(0.5)Ti_(0.5))O_3-(0.9-x)CaTiO_3-x(Li_(0.5)Sm_(0.5))TiO_3(LMT-CT-LST,摩尔比x=0.1~0.6)系列微波介质陶瓷,并研究该系列微波介质陶瓷的物相结构、表面形貌及微波介电性能。X线衍射(XRD)研究表明,所有的LMT-CT-LST样品均为钙钛矿结构。扫描电镜(SEM)表明,随着(Li_(0.5)Sm_(0.5))TiO_3含量的增加,样品的晶粒尺寸会不断增加。当x=0.6时,有些晶粒会出现异常长大现象,这对样品的微波介电性能有很大的影响。介电性能研究结果显示,随着(Li_(0.5)Sm_(0.5))TiO_3含量从0.1增加至0.6,介电常数(εr)略微从121.56减小至117.5,而对应的品质因数(Q×f)从10 055.71GHz降低至4 042.15GHz;此外,该体系谐振频率温度系数(τf)随(Li_(0.5)Sm_(0.5))TiO_3含量的增加逐渐向负值方向移动。当x=0.6时,复合陶瓷在1 340℃烧结4h,可获得最佳的综合微波介电性能,即ε_r≈117.5,Q×f≈4 042.15GHz(f=3.415 GHz),τ_f≈10.13×10-6/℃。
[Abstract]:A series of microwave dielectric ceramics were prepared by traditional solid state synthesis method. The series of microwave dielectric ceramics were prepared by the traditional solid state synthesis method. The phase structure, surface morphology and microwave dielectric properties of the microwave dielectric ceramics, such as the phase structure, surface morphology and microwave dielectric properties of the microwave dielectric ceramics, were studied by means of X-ray diffraction (XRD). All the LMT-CT-LST samples are perovskite structure. SEM (SEM) shows that the grain size of the LMT-CT-LST samples will increase with the increase of the content of LiSZ 0.5SmSq / TiO3.When x0. 6, some grains will grow abnormally. This has a great effect on the microwave dielectric properties of the samples. The results of the dielectric properties study show that with the increase of the content of TiO3 from 0.1 to 0.6, the dielectric constant (蔚 r) decreases slightly from 121.56 to 117.5, and the corresponding quality factor Q 脳 f decreases from 10 055.71 GHz to 4 042.15 GHz; in addition, the dielectric constant (蔚 r) is slightly reduced from 121.56 to 117.5 GHz to 4 042.15 GHz, and the corresponding quality factor Q 脳 f decreases from 10 055.71 GHz to 4 042.15 GHz. The temperature coefficient of resonance frequency (蟿 f) of the system moves gradually to a negative direction with the increase of the content of TiO3. The optimum comprehensive microwave dielectric properties can be obtained when the composite ceramics are sintered at 1 340 鈩，

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