Phase formation and characterization of high Curie temperature xBiYbO3–(1−x)PbTiO3 piezoelectric ceramics

Solution combustion synthesis and characterization of lead-free piezoelectric sodium niobate (NaNbO3) powders

“…This NaNbO 3 phase ( ) was consistent with JCPDS file no. 82-0606, which corresponded to an orthorhombic structure with the space group, P2 1 ma (26). For a fuel-rich condition (fuel-to-oxidizer molar ratio of 0.7, 0.8 and 0.9), the NaNbO 3 phase ( ) was detected with the accompanying pyrochlore phase of Na 2 Nb 4 O 11 ( ), which matched JCPDS file no.…”

“…From this ratio, the volume fraction of the perovskite phase formation (%perovskite) of as-prepared powder was found to be as high as 93%. This relative value was considered by approximately calculating the ratio of the main X-ray peak intensities of NaNbO 3 and Nb 2 O 5 phases [26], according to the following equation; % perovskite = (I perovskite /(I perovskite + I Nb 2 O 5 )) × 100. Thus, the as-prepared powder was calcined at different temperatures for 4 h with a heating/cooling rate of 20 • C/min.…”

Phase Transition Behavior of the (1−x)PbZrO3−xBa(Al1/2Nb1/2)O3 Solid Solution

“…In a ferroelectric perovskite, with t being equal to 1, the packing is expected to be ideal for cubic symmetry. When t is <1, the ferroelectric perovskite is usually rhombohedral or has monoclinic symmetry . According to the calculation of t in Table , when BAN concentration increased, t increased until it approached 1, which related to the ideal cubic perovskite structure, where t = 1.0 .…”

Phase transitional behavior and piezoelectric properties of BiYbO3–Pb(Ti0.5Zr0.5)O3–LiNbO3 ceramics

“…And the amounts of Yb 2 Ti 2 O 7 pyrochlore phase is stable with the increasing content of LiNbO 3 . As to BiYbO 3 -PbTiO 3 ceramics, our early research shows that it is difficult to synthesize pure perovskite phase by traditional method [16]. Because the BiYbO 3 compound owns a small tolerance factor 0.857, perovskite with such tolerance factor is known to be difficult to synthesise and second phases often appear.…”

“…In our early research, BiYbO 3 -PbTiO 3 crystalline solutions were fabricated and BiYbO 3 -PbTiO 3 ceramics with high Curie temperatures of >500 8C are obtained. But the problem is that the piezoelectric constant d 33 is only 28 pC/N [16].…”