National Engineering Research Center of Electromagnetic Radiation Control Materials, University of Electronic Science and Technology of China, Chengdu, 610054, China.
Dalton Trans. 2018 Nov 13;47(44):15808-15815. doi: 10.1039/c8dt03134g.
NdNb1-x(Al1/3W2/3)xO4 (x = 0.03-0.07) solid solution compounds were synthesized and characterized via solid-state reaction. XRD patterns reveal the formation of a single fergusonite phase, and the dependence of microwave dielectric properties on its structural characteristic was investigated based on Rietveld refinements together with complex chemical bond theory. The variation of dielectric constant is attributed to the Nb/Al1/3W2/3-O bond ionicity. The grain size and total lattice energy are both associated with quality factor, and the temperature coefficient is affected by oxygen and bond valence of the Nb site. Infrared reflectivity spectrum analysis illustrated that the permittivity is primarily due to ion polarization in the microwave frequency region. Notably, the following properties of NdNb1-x(Al1/3W2/3)xO4 (x = 0.04) ceramics were obtained: εr ∼ 19.04, Q × f ∼ 58 219 GHz and τf ∼ -41.14 ppm/°C.
采用固态反应法合成并表征了 NdNb1-x(Al1/3W2/3)xO4（x = 0.03-0.07）固溶体化合物。XRD 图谱表明生成了单一的铁镁尖晶石相，并基于 Rietveld 精修和复杂化学键理论研究了其结构特性对微波介电性能的影响。介电常数的变化归因于 Nb/Al1/3W2/3-O 键的离子性。晶粒尺寸和总晶格能都与品质因数有关，而氧和 Nb 位的键价则影响温度系数。红外反射光谱分析表明，在微波频率范围内，介电常数主要归因于离子极化。值得注意的是，NdNb1-x(Al1/3W2/3)xO4（x = 0.04）陶瓷具有以下性能：εr∼19.04、Q×f∼58219GHz 和 τf∼-41.14ppm/°C。
