Crystal structure, vibration spectra and microwave dielectric properties for scheelite structure NaSrLa(WO4)3 ceramics and adjustment of its τf value

作者：Deng, Haiqing; He, Yinghan; Wei, Xiaoli; Chen, Weilin; Liu, Yang; Chen, Xiuli^*; Zhou, Huanfu^*

来源：Journal of Materials Science: Materials in Electronics , 2023, 34(29): 1998.

DOI：10.1007/s10854-023-11406-6

• BOND-VALENCE PARAMETERS
• PHONON CHARACTERISTICS
• PACKING FRACTION
• PHASE-STRUCTURE
• MO
• COMPOSITES
• EVOLUTION
• BI

With expanding the working frequency of 5G wireless communication equipment to high-frequency millimeter wave, exploring microwave dielectric ceramics with low relative permittivity (epsilon(r) < 15) and high quality factor have become a current research hotspot. In this paper, the crystal structure of NaSrLa(WO4)(3) (NSLW) ceramics prepared by a solid state reaction method were studied by X-ray diffraction (XRD). XRD and Rietveld refinement results confirmed the formation of tetragonal NSLW single-phase with I4(1)/a space group. The relationship between the microwave dielectric properties and sintering temperature of NSLW ceramics was investigated. The epsilon(r) and quality factor were affected by bulk density, packing fraction and cation ordering degree, respectively. The tau(f) value was related to the bonding valence of W-O. The vibration characteristics were studied by Raman spectroscopy, and WO4 vibration was dominant. NSLW ceramics sintered at 1225 degrees C show excellent dielectric properties: epsilon(r) = 8.81, Qxf = 56,056 GHz (at 11.48 GHz), tau(f) = - 54.82 ppm/degrees C. By compounding with CaTiO3, a near-zero tau(f) were obtained for 0.92NSLW-0.08CaTiO(3) composite ceramics with optimized performance (epsilon(r) = 13.38, Qxf = 8928 GHz, tau(f) = - 0.39 ppm/degrees C) sintered at 1250 degrees C, exhibiting potential application prospects in 5G technique.

• 单位
  桂林理工大学