Crystal structure characteristics, dielecric properties and vibrational spectra of Nb-rich non-stoichiometric Ba[(Zn1/3Nb2/3)1−xNbx]O3 ceramics

Nb-Rich non-stoichiometric Ba(Zn 1/3 Nb 2/3 ) 1−x Nb x O 3 (BZNN) ( x = 0.01, 0.02, 0.03, 0.04) ceramics were synthesized using solid-state reaction method. Crystal structures and morphologies were analyzed by X-ray diffraction (XRD) and scanning electron microscopy methods. Vibrational modes were obtained by both Raman spectroscopy and Fourier transform far-infrared reflection (FTIR) spectroscopy. The relationship among crystal structures, dielectric properties, and phonon modes were analyzed in detail. XRD results showed that the main phase of BZNN is Ba(Zn 1/3 Nb 2/3 )O 3 , and the cell volume and lattice parameter reach a minimum value where x = 0.02. The Raman results displayed that two new modes appeared at about 200 cm − 1 where x > 0.01, which showed that structures of BZNN transform from 1:1 to 1:2 ordering with increasing Nb contents. FTIR results demonstrated that great changes took place for the shape of the bands below 180 cm −1 . The FTIR spectra were subjected to the Kramers–Krönig analysis.