Dielectric and structural studies of a SiO2–Li2O–Nb2O5 glass and glass-ceramic prepared by the sol–gel method

Synthesis and characterization of fine lithium niobate powders by sol‐ gel method

“…Traditional solid-state reactions (between Nb 2 O 5 and Li 2 CO 3 ) need high temperature, e.g., above 1200°C, which can cause the serious evaporation of Li 2 O component, it is hard to prepare SLN single crystals [3,7]. Sol-gel method has many unique advantages such as lower preparation temperature, easier composition control, and better homogeneity to prepare LN nanocrystal powders, glass-ceramics and LN-based ceramics [1,[8][9][10][11][12]. In our present work, we successfully obtained the fine LN nanocrystal powders using NbCl 5 as niobium source and LiAC.2H 2 O as lithium source, and the powders were characterized by Fourier transform infrared (FTIR), X-ray diffraction (XRD) and transmission electronmicroscopy (TEM).…”

Structural and electrical characteristics of LiNbO3 embedded in a 34% SiO2 glass matrix

“…6 shows the Cole-Cole plot using the Z * formalism, for all samples, at 300 K. A quantitative characterization of the dielectric measurements was made using a complex non- Table 2 The parameters of the equivalent electric circuit linear least squares (CNLLS) algorithm associated with the Levenberg-Marquardt method. 6,10 This software adjusts the frequency dispersion data to an equivalent electric circuit model presented in Fig. 7, which is basically constituted by the parallel combination of polarization resistance (R) and constant phase element (CPE) of the sample (R//CPE) in series with the parallel combination of the R e resistance and the CPE e element, which are associated with the electrodes.…”

“…The impedance of this intuitive element can be defined by 1/Z CPE = Q 0 (jω) n where Q 0 ([Q 0 ] = Fs n−1 ) and n (0 ≤ n ≤ 1) are adjustable parameters independent of the frequency. 6,10,[22][23][24] All samples, with the exception of the HT600, present semiarcs whose centers are below the Z -axis, indicating the existence of a relaxation time distribution. [22][23][24] This behaviour must be related to the fact that in these systems the dielectric response depends on several components such as the glass matrix, the LiNbO 3 crystals, the dipoles related to the glass-modifier ions and the dipoles arising from the interface electrode-sample surface.…”

Study of the electric and dielectric properties of SiO2–Li2O–Nb2O5 sol–gel glass–ceramics

“…It is of scientific and technological interest produce glass-ceramics with LiNbO 3 crystals [2,3] to avoid the high cost and growing time of these crystals in bulk. The preparation of the glass by the sol-gel method presents, relatively to the melting method, the advantage of allowing the synthesis of new glass compositions [4][5][6].…”

“…This composition was chosen for the following reasons: (1) SiO 2 is a glass forming oxide that does not modify the LiNbO 3 lattice, (2) the LiNbO 3 stoichiometry allows the use of equal amounts of Li 2 O and Nb 2 O 5 , (3) we have already studied the 92SiO 2 -4Li 2 O-4Nb 2 O 5 (mol%) composition [6].…”