Publisher’s Note: “Landau–Devonshire derived phase diagram of the BiFeO3–PbTiO3 solid solution” [J. Appl. Phys. 127, 104102 (2020)]

Role of magnetic ordering in the phase coexistence at the structural instability of the multiferroic BiFeO3–PbTiO3

“…It is also surprising the lower Tc of the R3c phase as compared to that of P4mm one, considering the much higher Tc of its isostructural BiFeO3 edge composition (~830 ºC) in relation to the tetragonal PbTiO3 one (490 ºC). 28,29 Large differences in transition strain among these polymorphs must be behind the peculiar ferroelectric instability of this MPB binary system, for which a huge tetragonal distortion of cT / aT ~1.18 and an abrupt change of lattice volume has been described when moving compositionally from one polymorph to other within the phase diagram. 40 A different scenario emerges for the quenched material, whose majority phase was the tetragonal phase at room temperature.…”

“…[24][25][26] It presents a MPB analogous to that of BiFeO3-BiCoO3, characterized by a strongly discontinuous transition with composition at about 0.7BiFeO3-0.3PbTiO3 between polymorphs of P4mm (at the PbTiO3-rich side) and R3c (at the BiFeO3rich one) symmetries. 27,28 A controversy persists as regards the actual symmetry of the latter polymorph, for several studies using Rietveld refinements of x-ray diffraction (XRD) data have indicated that it could be monoclinic Cc for compositions close to the MPB. 29,30 This also supported by a number of distinctive features that seem characteristic of monoclinic symmetry, like a magnetic spin reorientation transition, 31 or the existence of lattice transverse softening.…”