Structural, thermal and microwave dielectric properties of the novel microwave material Ba2TiGe2O8
Structural, thermal and microwave dielectric properties of the novel microwave material Ba2TiGe2O8
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新型微波材料Ba2TiGe2O8的结构、热学和微波介电性能
DOI：
10.1016/j.ceramint.2018.03.127
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发表时间：
2018
影响因子：
5.2
通讯作者：
Jantunen Heli
中科院分区：
文献类型：
--
作者：
Xiang Huaicheng;Bai Yang;Li Chunchun;Fang Liang;Jantunen Heli
近年来，由于微波介质材料的广泛应用和无线通信技术的革新，微波介质材料得到了迅速的发展。然而，许多商业微波材料是基于钛酸盐、钛酸盐和钽酸盐的，其具有原料昂贵和烧结温度高的缺点。这导致生产过程不节能。本文从BaO-TiO_2二元系出发，发展了BaO-TiO_2-GeO_2三元系，以获得低温共烧高频微波介质陶瓷。采用传统固相法制备了Ba 2 TiGe 2 O 8陶瓷。X射线衍射结果表明，Ba 2 TiGe 2 O 8属于正交晶系，Cmm 2空间群。在1060 °C烧结后，陶瓷的致密化率为96.3%。它们的相对介电常数（εr）为12.7，品质因子（Q×f）为9060 GHz（10 GHz时），谐振频率温度系数（τf）为-30 ppm/°C，热膨胀系数（CTE）为11.0 ppm/°C。此外，还研究了Ba_2TiGe_2O_8晶胞的拉曼光谱和离子极化率。
Rapid developments of microwave dielectric materials have emerged in recent years due to their wide-spread applications and the revolution in wireless communications. However, many commercial microwave materials are based on titanates, niobates and tantalates which have the disadvantages both of costly raw materials and high sintering temperatures. These result in a production process which is not energy efficient. In this paper we develop a BaO-TiO2-GeO2ternary system derived from the BaO-TiO2binary system to obtain low temperature co-fired microwave dielectric ceramics for high frequency applications. The Ba2TiGe2O8ceramics were prepared via the conventional solid-state route. The X-ray diffraction results showed that Ba2TiGe2O8belongs to the orthorhombic,Cmm2space group. The ceramics exhibited a densification of 96.3% after being sintered at 1060 °C. They also exhibited a relative permittivity (εr) of 12.7, a quality factor (Q×f) of 9060 GHz (at 10 GHz), a temperature coefficient of resonant frequency (τf) of −30 ppm/°C and a coefficient of thermal expansion (CTE) of 11.0 ppm/°C. In addition, the Raman spectra and ionic polarizability of Ba2TiGe2O8unit cells were investigated.