Influence of A‐site nonstoichiometry on the electrical properties of BT‐BMT

Abstract

A stoichiometric and 2 mol% Ba deficient samples in the formulation 0.5BaTiO3‐0.5BiMg1/2Ti1/2O3 (BT‐BMT) were processed via a mixed oxide solid‐state route. The deficient sample exhibited a high relative permittivity (2100±15%) over the temperature range 90‐450°C and a low dielectric loss (tanδ < 0.01), maintained up to high temperature (430°C). The samples exhibited intrinsic conduction mechanism and showed an n‐type character. By introducing 2 mol% Ba vacancies, a dramatic influence on the dielectric loss was observed which was mainly associated with the trapping of electrons by barium‐oxygen vacancy pair associated with the intentionally produced cation vacancies. Thus, control of composition by creating deficiency allows fine tuning of the dielectric properties of BT‐BMT ceramics for applications in high‐temperature multilayered ceramic capacitors.

Temperature Stable Dielectric Properties in BaTiO3–Bi(Mg2/3Nb1/3)O3–NaNbO3 Solid Solution

“…Room temperature Raman spectra of BT–BMN–NN samples are shown in Figure . A total number of five bands were observed, consistent with the previous study . The first sharp bands appeared at ∼114 cm −1 and 174 cm −1 which may be due to the movement of A‐site cations, showing a short‐range ferroelectric order due to the cations enriched nano‐clusters due to the occupancy of multiple cations at the same site .…”

“…A total number of five bands were observed, consistent with the previous study. [19] The first sharp bands appeared at ∼ 114 cm À 1 and 174 cm À 1 which may be due to the movement of A-site cations, showing a short-range ferroelectric order due to the cations enriched nano-clusters due to the occupancy of multiple cations at the same site. [20] A dip in the pure tetragonal-BT is always found near 180 cm À 1 which indicates the ferroelectric behavior, which was not observed in present case, indicating the formation of paraelectric phase; however, broadening in the peak ∼ 300 cm À 1 was found which indicates that there is no long-range ferroelectric order because a sharp peak is generally observed in tetragonal-BT as reported.…”

Dielectric, ferroelectric and optical properties of Na and Nb co-doped (Bi0.5Na0.5)0.94Ba0.06TiO3

“…The Raman spectra is similar to that of previously reported for the BNT-NN [23]. The peak near ~114 cm -1 is assigned as a A1(TO1) mode which is due to the vibration of A-site cations [24]. The band near ~261 cm -1 is dominated by Ti-O vibration are assigned as E(TO2).…”

Effect of Sb-site nonstoichiometry on the structure and microwave dielectric properties of Li3Mg2Sb1−xO6 ceramics

“…Similar phenomena were also reported in other materials [18]. In addition, as seen in Table 1, the cell volume was enlarged when x increased from 0.05 to 0.125, which is due to the increased concentration of V o caused by Sb 5+ ion defects [19,20]. Figure 2 gives the refined XRD plots for Li 3 Mg 2 Sb 0.9 O 6 specimens heated at 1200-1275 ℃.…”