Microstructure, chemical bond characteristics, and dielectric response of Cr/Sb co-doped molybdate-based ceramics at microwave and terahertz frequency
Microstructure, chemical bond characteristics, and dielectric response of Cr/Sb co-doped molybdate-based ceramics at microwave and terahertz frequency
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DOI：
10.1016/j.ceramint.2023.02.099
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发表时间：
2023-04-21
影响因子：
5.2
通讯作者：
Yue, Zhenxing
中科院分区：
文献类型：
--
作者：
Feng, Zhanbai;Guo, Weijia;Yue, Zhenxing
本研究通过在Ce2Zr3(MoO4)9陶瓷中共掺Cr/Sb来优化其微波介电性能，并探讨其内在机理。所有的陶瓷都是用传统的陶瓷方法合成的，研究了Cr/Sb对陶瓷的微观结构、化学键特性、声子振动光谱和微波和太赫兹频率下的介电响应的影响。X-射线衍射分析表明，所有样品均为三方晶系，没有观察到额外的峰。根据所观察到的烧结行为，在875℃获得了致密的陶瓷。Cr/Sb的共同加入显著降低了基质的介电损耗。因此，从本征因素的角度对介电参数进行了讨论。化学键分析结果表明，Zr(Cr/Sb)-O键与材料的微波介电性能密切相关，并且Cr/Sb优先占据在Zr(1)位上。红外光谱分析表明，400 cm-1以下的声子振动对偏振的贡献率为72.1%。在红外光谱和太赫兹时间域(THz-TD)谱的比较中，我们发现后者提取的介电常数更接近观测值。在Ce_2[Zr0.98(Cr0.5Sb0.5)0.02]_3(MoO_4)_9陶瓷中，获得了较好的介电常数r=10.53，qf=72,656 GHz，tau f=-16.77ppm/度C。
In this research, Cr/Sb was co-doped in Ce2Zr3(MoO4)9 ceramic to optimize the microwave dielectrics and explore the intrinsic mechanism. All ceramics were synthesized using the traditional ceramic method to inves-tigate the effects of Cr/Sb on the microstructure, chemical bond characteristics, phonon vibration spectra, and dielectric response at microwave and terahertz frequencies. X-ray diffraction analysis identified that all samples crystallized in a trigonal system, and no additional peaks observed. The dense ceramic was obtained at 875 degrees C based on the observed sintering behaviors. The co-addition of Cr/Sb significantly reduced the dielectric loss in the matrix. Therefore, dielectric parameters were discussed in terms of intrinsic factors. The findings of chemical bond indicate that Zr(Cr/Sb)-O bonds possess a close relationship with microwave dielectric properties, and Cr/ Sb is occupied preferentially on the Zr(1) sites. Infrared spectrum analysis identified that phonon vibration lower than 400 cm-1 contribute 72.1% to the polarization. In our comparison between the infrared spectrum and terahertz time-domain (THz-TD) spectrum, we found that the permittivity extracted by the latter is closer to the observed value. Consequently, the outstanding parameters of epsilon r = 10.53, Qf = 72,656 GHz, tau f =-16.77 ppm/degrees C were obtained in the Ce2[Zr0.98(Cr0.5Sb0.5)0.02]3(MoO4)9 ceramic.