Phase evolution in (1−x)(Na0.5Bi0.5)TiO3-xSrTiO3 solid solutions: A study focusing on dielectric and ferroelectric characteristics

Dielectric temperature stability and energy storage performance of NBT‐based ceramics by introducing high‐entropy oxide

“…According to the analysis by Jade software, the second phase is determined to be Bi 2 Sn 2 O 7 (PDF card 56‐0646). In addition, no splitting is found in the (1 1 1)/(2 0 0) diffraction peaks for all studied compositions, which indicates that the phase structure of NBT ceramics is transferred from a rhombohedral phase to a cubic phase by introducing the HEPO SZSHTN 17,42 . Relevant tolerance factors and lattice parameters of (1− x )NBT– x SZSHTN ( x = 0.15–0.35) ceramics have been plotted in Figure S1.…”

A novel relaxor (Bi,Na,Ba)(Ti,Zr)O3 lead‐free ceramic with high energy storage performance

“…Within this scenario, the PNRs should happen because such compositions (BNT counterpart takes up a proportion of 50%-90%) always involve a mixed contribution by a transformation of R3c↔P4bm and a thermal evolution of P4bm PNRs. 24,25 These diffraction lines apparently shift toward lower 2θ angles with the increase in BZT component. This is reasonable that the incorporated Ba 2+ (R Ba 2+ = 161 pm) and Zr +4 (R Zr +4 = 72 pm) cations have the larger ionic radii than those of the original (Na 0.5 Bi 0.5 ) +2 (R (Na0.5Bi0.5) 2+ = 144 pm)…”

“…This phase in BNT system is characterized in a static relaxor behavior that is associated with the low-temperature PNRs, but highly correlated with the high-temperature dynamic PNRs dominated by the R3c↔P4bm transformation. 25,34 With increasing the component BZT (i.e., x), the ε max values are depressed and meanwhile, the T m shifted toward lower temperature under a certain frequency, for example, T m decreases from 119°C (x = 0.30) to 54°C (x = 0.50) at 1 kHz that is significantly lower than that of the pure BNT with a Tc ~220°C, and ε max correspondingly falls from 2899 to 1525. One important reason involved is that BZT has a quite low T c of near −50°C.…”

“…Figure 2B exhibits the enlarged patterns around 2 θ = 45‐46° that reflect no diffraction splitting lines, which can be indexed to be the (002) diffraction line of a pseudo‐tetragonal phase with a main space group of P 4 bm . Within this scenario, the PNRs should happen because such compositions (BNT counterpart takes up a proportion of 50%‐90%) always involve a mixed contribution by a transformation of R 3 c ↔ P 4 bm and a thermal evolution of P 4 bm PNRs 24,25 . These diffraction lines apparently shift toward lower 2 θ angles with the increase in BZT component.…”

“…Thus, this T m can be attributed to a process of dielectric relaxation resulting from thermal activation of PNRs with exhibiting the P 4 bm pseudo‐phase, which again verifies the XRD determinations (Figure 2) where no diffraction line splitting was presented. This phase in BNT system is characterized in a static relaxor behavior that is associated with the low‐temperature PNRs, but highly correlated with the high‐temperature dynamic PNRs dominated by the R 3 c ↔ P 4 bm transformation 25,34 . With increasing the component BZT (i.e., x ), the ε max values are depressed and meanwhile, the T m shifted toward lower temperature under a certain frequency, for example, T m decreases from 119°C ( x = 0.30) to 54°C ( x = 0.50) at 1 kHz that is significantly lower than that of the pure BNT with a Tc ~220°C, and ε max correspondingly falls from 2899 to 1525.…”