Origin and magnitude of the large piezoelectric response in the lead-free (1–x)BiFeO₃–xBaTiO₃ solid solution

Abstract

Abstract

Stable piezoelectric property of modified BiFeO3–BaTiO3 lead-free piezoceramics

“…1, XRD diffraction peaks at 32°and 39°were fitted well with two Voigt-shaped peaks for both samples. Referring to BiFeO 3 in rhombohedral structure and structural evolution in the BF-BT binary solid solution [17][18][19][20][21][22][23][24], it is concluded that both pure and 0.26 wt% MnO 2 -doped BF69.6-BZT1.4-BT29 samples are crystallized in rhombohedral perovskite structure, of which the splitting degree of the diffraction peaks around 39°are closely associated with rhombohedral distortion degree. Meanwhile, no secondary phases of Bi 25 FeO 39 and Bi 2 Fe 4 O 9 often met in the BiFeO 3 -based systems were detected out, which implies that BZT diffuses into BF-BT lattice and single perovskitetype phase is obtained here, in agreement with previous observations [28][29][30].…”

“…Wherein, XRD measurements showed them to be pseudo-cubic phase. In the studies of composition-dependent structure of BF-BT binary solid solutions, the reported critical composition for structural phase boundary between rhombohedral and pseudocubic phase is very different, of which 0.725BF-0.275BT, 0.67BF-0.33BT, or a transition region between 0.25BT and 0.33BT has been reported till now [17][18][19][22][23][24]. Referring to Figs.…”

“…While, a maximum piezoelectric property of d 33 = 124 pC/N, e 33 T / e 0 = 760, tand = 0.078, and k p = 0.29 was reported at optimum composition of 0.725BF-0.275BT, i.e., at structural phase boundary between rhombohedral and pseudocubic [24]. Till now, extensive studies have reported different composition of structural phase boundary between rhombohedral and pseudocubic of x = 0.275, [24] x = 0.33 [17,18] or over the range of x = 0.25-0.33 [22,23]. It is of interest to note that, even though Mn-doping strategy is effective to decrease dielectric loss, dielectric loss of BF-BT ceramics reported so far is still far away from practical level of tand B 0.02.…”

“…For 0.1 wt% MnO 2 -doped 0.67BF-0.33BT (0.75BF-0.25BT) ceramics, a piezoelectric property of d 33 = 70 (116) pC/N, e r = 750 (557), tand = 0.068 (0.046), and T C = 605°C (619°C ) was reported [22,23]. While, a maximum piezoelectric property of d 33 = 124 pC/N, e 33 T / e 0 = 760, tand = 0.078, and k p = 0.29 was reported at optimum composition of 0.725BF-0.275BT, i.e., at structural phase boundary between rhombohedral and pseudocubic [24].…”

Lead-free piezoceramics: Status and perspectives

“…While the first publications on bismuth ferrite-barium titanate (BF-BT) are already several years old, 28 there has been recent progress by a number of researchers. Most appealing is the promise for use of BF-BT at high temperatures, not only replacing PZT, but also considerably improving high-temperature capabilities.…”