Crystal chemistry and domain structure of rare-earth doped BiFeO3 ceramics

Structural and magnetic properties of isovalently substituted multiferroic BiFeO3: Insights from Raman spectroscopy

“…On the other hand, Troyanchuk et al 18 observed a similar antipolar, probably incommensurate, structure all the way between 20% and 45% La. A PbZrO 3 -type structure was also observed by Karimi et al 17 when 20% Nd and 15% Sm was introduced at the A site.…”

“…15 A similar transition, albeit more complicated, is reported in the intensely studied Bi 1−x La x FeO 3 series. 5,[16][17][18][19] Here the similar ionic radii between Bi and La makes it possible to stabilize several intermediate structures before the final P nma structure is reached at 50% La content. 16 XRD and electron diffraction (ED) data indicated a stabilized R3c structure up to 20% La content where a transition towards a P nma structure of the GdFeO 3 type occurred.…”

“…16 XRD and electron diffraction (ED) data indicated a stabilized R3c structure up to 20% La content where a transition towards a P nma structure of the GdFeO 3 type occurred. 17 However, a more recent study, also employing a combination of synchrotron XRD and ED, reported a total of four structural phases. 16 A single phase R3c structure was reported up to x = 0.1, followed by a mixed phase region for x < 0.18.…”

“…To our knowledge, Raman spectra on Bi 1−x Tb x FeO 3 and Bi 0.9 Sm 0.1 Fe 1−x Mn x O 3 have not been published before, while Bi 1−x La x FeO 3 has only been investigated to some extent with this technique. 17,36 The reported Raman spectra of Bi 1−x La x FeO 3 are in fact difficult to reconcile with the aforementioned diffraction data, as they have been interpreted as showing R3c symmetry up to 20% La content and broadened P nma spectra above. 17,36 Here we alleviate the discrepancies between Raman and diffraction experiments and show Raman spectra corresponding to a single R3c phase for x 0.1, P nma for x 0.5, a PbZrO 3 -type structure for 0.175 x 0.4, and a mixed R3c-PbZrO 3 phase for x = 0.15.…”

Piezoelectric nonlinearity and frequency dispersion of the direct piezoelectric response of BiFeO3 ceramics

“…[1][2][3] Owing to its rhombohedral structure, the ferrite has been considered as an end-member of a variety of leadfree solid solutions exhibiting morphotropic phase boundary (MPB), which is believed to be the key for obtaining high piezoelectric properties. Some recently studied systems are BiFeO 3 -REFeO 3 (RE = La, Nd, Sm, Gd, Dy), [4][5][6] BiFeO 3 -BaTiO 3 , 7,8 and BiFeO 3 -Bi(Zn 0.5 Ti 0.5 )O 3 . 9 In addition, the high T C of BiFeO 3 enables to design MPB compositions suitable for high-temperature piezoelectric applications, such as the recently emerged BiFeO 3 -PbTiO 3 .…”