Simultaneous enhancement of electrical and mechanical properties in CaBi2Nb2O9-based ceramics

Insight into the Ultrahigh Electric Performance of Aurivillius CBTa-CBN Solid Solution

“…In Figure b, eight peaks are used to fit the curves of Ce 3d, denoted as ν, ν′, ν″, ν‴, μ, μ′, μ″, and μ‴, confirming that the Ce ion coexists in +3 and +4 valence states . Among them, the peaks of ν and μ, ν″ and μ″ are related to Ce 3+ , while the peaks of ν′ and μ′, ν″′, and μ″′ correspond to Ce 4+ . From the high-resolution spectrum of Nb3 d (Figure c), it can be seen that with the increase of x content, the strength of peak Nb 3d enhances gradually, indicating Nb 5+ substitution for Ta 5+ .…”

“…Therefore, the larger XPS spectra of Ce 3d for LCCBTa-0.0CBN, LC-CBTa-0.4CBN, and LC-CBTa-1.0CBN ceramics are given in Figure b. In Figure b, eight peaks are used to fit the curves of Ce 3d, denoted as ν, ν′, ν″, ν‴, μ, μ′, μ″, and μ‴, confirming that the Ce ion coexists in +3 and +4 valence states . Among them, the peaks of ν and μ, ν″ and μ″ are related to Ce 3+ , while the peaks of ν′ and μ′, ν″′, and μ″′ correspond to Ce 4+ .…”

“…9 Among them, the peaks of ν and μ, ν″ and μ″ are related to Ce 3+ , while the peaks of ν′ and μ′, ν″′, and μ″′ correspond to Ce 4+ . 9 From the high-resolution spectrum of Nb3d (Figure 5c), it can be seen that with the increase of x content, the strength of peak Nb 3d enhances gradually, indicating Nb 5+ substitution for Ta 5+ . Figure 5d−f exhibits the high-resolution spectrum of O 1s for samples with x = 0.0, 0.4, and 1.0, respectively.…”

“…In addition, the volatilized Bi 2 O 3 under a high sintering temperature environment will generate a large number of oxygen vacancies, producing increased carrier concentration and hampering polarization switching. To obtain excellent electric performances of BLSFs, great efforts have been paid to improve their comprehensive electrical properties, mainly including composition modification and grain orientation technologies [hot pressing (HP), spark plasma sintering (SPS), and template grain growth (TGG)]. − Between these tailoring methods, chemical modification is considered a comprehensive cost-effective method due to its simple fabrication process and enhanced result possibilities. − For Na 0.5 Bi 4.5 Ti 4 O 15 (NBT) ceramics, good electrical performance was obtained via Nd 3+ doping with a T C of 670 °C, d 33 of 24.5 pC/N, and P r of 10.8 μC·cm –1 . With W 6+ doping, the d 33 of CaBi 4 Ti 4 O 15 (CBT) was enhanced to 17.8 pC/N, which is two times larger than that of pure CBT ceramics .…”

Utilization of Nonstoichiometric Nb5+ to Optimize Comprehensive Electrical Properties of KNN-Based Ceramics

“…Thus, the in situ temperature dependence of the d 33 for the poled KNN x T-BNZ-BFO ceramics is measured, as shown in Figure e. As the test temperature increases, the d 33 values of all ceramics drop sharply and then slowly due to the aligned domain variation under thermal excitation , and the crystal symmetry variation . Previous studies have shown that the phase structure of KNN-based ceramics changed from multiphase coexistence to dominated T phase with increasing temperature , and the domain orientation is destroyed due to thermal excitation, which leads to the d 33 values of the ceramics drop sharply in the temperature range of 30–150 °C.…”