xLiVO2-(1-x)Li2TiO3复相微波介质陶瓷的制备与性能研究

Study on the preparation and properties of xLiVO2-(1-x)Li2TiO3 composite microwave dielectric ceramics

  • 摘要: 为了降低钛酸锂微波介质陶瓷的烧结温度,本研究采用固相烧结法成功制备了xLiVO2-(1-x)Li2TiO3复相微波介质陶瓷(x值为0.025-0.20)。通过研究了不同LiVO2添加量及烧结温度下的复合陶瓷烧结行为和相组成,探究了材料介电性能和温度稳定性的影响因素,研究发现随着LiVO2的掺入量提高,陶瓷的谐振频率温度系数(τf)逐步降低,由正值转变为负值,当x=0.05时,获得了近零的谐振频率温度系数。而LiVO2的掺入量同样对于Q×f值有着决定性的影响,其中LiVO2的掺入量过高会对xLiVO2-(1-x)Li2TiO3二元体系陶瓷的Q×f值有着明显的劣化。而随着低熔点LiVO2的掺入,极大的降低了Li2TiO3体系陶瓷的烧结温度,纯Li2TiO3陶瓷的烧结温度为1200℃,xLiVO2-(1-x)Li2TiO3陶瓷的烧结温度仅为825℃-900℃。其中x=0.075的样品在850℃下烧结得到的样品的Q×f值为22505 GHz,τf =−12.79 ×10−6/℃,εr = 27.47。本研究在显著降低了烧结温度的同时,获得了具有较低谐振频率温度系数的xLiVO2-(1-x)Li2TiO3复相微波介质陶瓷。

     

    Abstract: To reduce the sintering temperature of lithium titanate-based microwave dielectric ceramics, this study successfully prepared xLiVO2-(1-x)Li2TiO3 composite ceramics (with x ranging from 0.025 to 0.20) via a solid-phase sintering method. The sintering behavior and phase composition of the composite ceramics were systematically investigated under varying LiVO2 additions and sintering temperatures, focusing on factors influencing dielectric properties and temperature stability. The results reveal that as the LiVO2 content increases, the temperature coefficient of resonant frequency progressively decreases, shifting from positive to negative values. A near-zero τf was achieved at x = 0.05. However, the LiVO2 content critically impacts the quality factor, and excessive LiVO2 significantly degrades the Q×f value of the xLiVO2-(1-x)Li2TiO3 binary system. Furthermore, incorporating low-melting-point LiVO2 substantially reduces the sintering temperature from 1200℃ (pure Li2TiO3) to 825–900℃. For the sample with x = 0.075 sintered at 850℃, optimal properties were attained: Q×f = 22,505 GHz, τf = −12.79 ×10−6/℃, εr = 27.47. This study successfully achieved xLiVO2-(1-x)Li2TiO3 composite microwave dielectric ceramics with a low temperature coefficient of resonant frequency while significantly reducing the sintering temperature.

     

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