Composition-structure-property relationships in CeZr1.14Bi0.045A0.045Mo4.5O18 (A = Nb, Ta and Sb) microwave dielectric ceramics revealed by Raman, far-infrared and terahertz spectra
Composition-structure-property relationships in CeZr1.14Bi0.045A0.045Mo4.5O18 (A = Nb, Ta and Sb) microwave dielectric ceramics revealed by Raman, far-infrared and terahertz spectra
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DOI：
10.1016/j.jmrt.2023.05.237
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发表时间：
2023-05
期刊：
影响因子：
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通讯作者：
Hailong Pan;Xu Zhou;Haitao Wu;Jialun Du;Z. Feng;M. Wübbenhorst
中科院分区：
文献类型：
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作者：
Hailong Pan;Xu Zhou;Haitao Wu;Jialun Du;Z. Feng;M. Wübbenhorst
了解组成-结构-性能关系对于新型微波介质陶瓷在无线通信领域的发展和应用至关重要。本文采用固相反应法制备了一系列CeZr 1· 14 Bi 0.045 A 0.045 Mo 4· 5 O 18（缩写为CZA，A= Nb、Ta和Sb）陶瓷。密度和扫描电子显微镜结果显示致密和均匀的显微结构。X射线衍射分析表明形成了固溶体。因此，本论文从内禀角度出发，结合化学键理论、拉曼光谱、远红外光谱和太赫兹时域光谱，系统地研究了材料的组成-结构-性能关系。有趣的是，测得的介电常数（ε r）和品质因数（Q× f）非常接近FIR和THz-TDS的外推值，并且这些值随着组件的变化显示出类似的趋势。此外，Mo-O键对热膨胀系数（α）和键能（E）起着重要作用，Mo-O键平均α和E的变化可以很好地解释组成对共振频率温度系数（τ f）的影响。通常情况下，在700° C下烧结的CCl_2陶瓷具有优异的性能，Q× f= 116，485 GHz（在9.58 GHz时），ε r= 9.91和τ f=− 19.20 ppm° C− 1。值得注意的是，CZTa和CZSb陶瓷的Q× f值分别是基体的6.13和4.16倍。超高Q× f、低烧结温度（600− 700° C）和低ε r使其成为低温共烧陶瓷（LTCC）应用的潜在候选材料。
Understanding composition-structure-property relationships is critical to developments and applications of novel microwave dielectric ceramics used in the field of wireless communications. Herein, a series of CeZr 1· 14 Bi 0.045 A 0.045 Mo 4· 5 O 18 (abbreviated as CZA, A= Nb, Ta and Sb) ceramics were prepared through a solid-state reaction method. Density and scanning electron microscope results revealed dense and homogeneous microstructures. X-ray diffraction analysis indicated the formation of solid solutions. Accordingly, the effects of extrinsic factors were negligible and thus composition-structure-property relationships were systematically investigated by the combination of the chemical bond theory, Raman spectroscopy, far-infrared (FIR) spectroscopy and terahertz time-domain spectroscopy (THz-TDS) from an intrinsic perspective. Interestingly, the measured dielectric constants (ε r) and quality factors (Q× f) are quite close to the extrapolated values from FIR and THz-TDS, and these values show a similar trend with varying components. In addition, Mo–O bonds play an important role in the coefficient of thermal expansion (α) and bond energy (E), and the composition dependent temperature coefficient of the resonance frequency (τ f) can be well explained by variations of mean α and E of Mo–O bonds. Typically, excellent properties of Q× f= 116,485 GHz (at 9.58 GHz), ε r= 9.91 and τ f=− 19.20 ppm° C− 1 were achieved for the CZSb ceramic sintered at 700° C. Notably, Q× f values of CZSb and CZTa ceramics are 6.13 and 4.16 times larger than that of the matrix, respectively. Ultra-high Q× f, low sintering temperatures (600− 700° C) and low ε r make them potential candidates for low temperature co-fired ceramics (LTCC) applications.