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Polarized Raman scattering and infrared dispersion analysis of Na 2 ZnGeO 4 ceramics
Author(s) -
Viegas Jéssica Ivone,
Moreira Roberto Luiz,
Dias Anderson
Publication year - 2020
Publication title -
journal of raman spectroscopy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.748
H-Index - 110
eISSN - 1097-4555
pISSN - 0377-0486
DOI - 10.1002/jrs.5927
Subject(s) - raman spectroscopy , dielectric , monoclinic crystal system , materials science , scanning electron microscope , analytical chemistry (journal) , infrared , ceramic , dispersion (optics) , raman scattering , infrared spectroscopy , spectroscopy , phonon , optics , chemistry , crystallography , crystal structure , condensed matter physics , optoelectronics , physics , organic chemistry , chromatography , quantum mechanics , composite material
Abstract The structural, chemical, morphological, and optical‐vibration properties of Na 2 ZnGeO 4 ceramic samples prepared by conventional solid‐state processing and sintered at 1,100°C are investigated in detail. X‐ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive spectroscopy (EDS), and electron energy‐loss spectroscopy (EELS) showed that single‐phase samples belonging to the monoclinic Pn (= C s 2 ) space group were obtained. Optical‐vibration investigations by polarized Raman and infrared spectroscopies altogether allowed us to present the characteristic features of the relevant polar phonons of the material, for the first time. Twenty‐nine out of the 45 optical modes predicted for Na 2 ZnGeO 4 by group theory were determined, and their symmetries are revealed. The dielectric strengths of the modes that contribute to the dielectric response were obtained. Besides, the infrared dispersion parameters allowed us to calculate the extrapolated dielectric constants ε 0 = 7.62 and ε ∞ = 2.80, and an intrinsic quality factor Q u × f = 154 THz, at 10 GHz. The obtained values show that this material can be classified as a low‐ k high‐ Q ceramics, which potential applications in microwave circuitry.