Microwave dielectric properties in the Li4+xTi5O12 (0 ≤ x ≤ 1.2) Ceramics
Microwave dielectric properties in the Li4+xTi5O12 (0 ≤ x ≤ 1.2) Ceramics
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Li4 xTi5O12 (0≤x≤1.2)陶瓷的微波介电性能
DOI：
10.1016/j.jallcom.2017.01.134
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发表时间：
2017
影响因子：
6.2
通讯作者：
Li Chunchun
中科院分区：
文献类型：
--
作者：
Li Wei;Fang Liang;Tang Ying;Sun Yihua;Li Chunchun
采用固相反应法制备了Li 4 + xTi 5 O 12（0 ≤x≤ 1.2）微波介质陶瓷。研究了掺杂量对材料相稳定性、微观结构和微波介电性能的影响。XRD分析表明，当x = 0时，不能得到纯的Li 4 Ti 5 O 12，只有少量的TiO 2作为第二相，而在x = 0.2-0.4范围内，形成了单相的Li 4 Ti 5 O 12固溶体。在0.6 ≤x≤ 1.2的范围内，Li 4 Ti 5 O 12和Li 2 TiO 3共存，Li 2 TiO 3相的数量随着掺杂浓度的增加而增加。微波介电性能强烈依赖于烧结温度和组成。在1000 °C下烧结的x = 1.2样品中，τfof +2.7 ppm °C接近零，aQ×fof 36，000 GHz，εrof 25.1，沿着。此外，添加0.5wt%B_2O_3，在940 °C烧结x = 1.2的样品，可获得具有热稳定性和与银化学相容性的低温共烧陶瓷（LTCC）材料。该材料具有良好的微波介电性能，ε r为28.0，Q × f为32，000 GHz，τ f为−7.8 ppm scin °C。
Microwave dielectric ceramics, with a Li4+xTi5O12(0 ≤x≤ 1.2) formula, were prepared using a conventional solid-state reaction method. The effects of doping amount on the phase stability, microstructure and microwave dielectric properties were investigated. The XRD analysis showed that atx= 0, pure Li4Ti5O12could not be obtained but with trace amount of TiO2as a secondary phase, while single phase of the Li4Ti5O12solid solution was formed inxrange of 0.2–0.4. The Li4Ti5O12and Li2TiO3coexisted in the compositions with 0.6 ≤x≤ 1.2 and the amount of Li2TiO3phase increased with increasing doping concentration. The microwave dielectric properties were strongly dependent on the sintering temperature and composition. A near-zeroτfof +2.7 ppm∕°C along with aQ×fof 36,000 GHz and aεrof 25.1 was obtained inx= 1.2 sample sintered at 1000 °C. Moreover, promising low temperature co-fired ceramic (LTCC) materials with thermal stability and chemical compatibility with silver can be obtained in thex= 1.2 sample with 0.5 wt% B2O3addition sintered at 940 °C. This material has good microwave dielectric properties withεrof 28.0,Q×fof 32,000 GHz andτfof −7.8 ppm∕°C.