Heterophase states and domain effects in solid solutions of (1 - x)BiFeO_3 - xPbTiO_3

摘要

Examples of heterophase states in multiferroic solid solutions of (1 - Jt)BiFeO_3 - xPbTiO_3 with the perovskite-type structure are studied taking into account the features of elastic matching of polydomain (twinned) ferroelectric phases near the morphotropic phase boundary and in a wide temperature range. Conditions for the complete stress relief are examined in the heterophase states PAmm-PAmm and PAmm-Cc to interpret variations of the phase content [S. Bhattacharjee et al., Phys. Rev. B 84, 104116 (2011)] [S. Bhattacharjee and D. Pandey, J. Appl. Phys. 110, 084105 (2011)] in (1-x)BiFeO_3-xPbTiO_3. The key role of some 90° domain types of the low-temperature ferroelectric PAmm phase in the stress relief at the phase coexistence is emphasized. An agreement between the evaluated and experimental data on the volume fraction of the low-temperature PAmm phase in heterophase samples is observed.