In situ study on enhanced plastic deformability of Lanthanum-doped Bismuth ferrite processed by flash sintering.

BiFeO 3 is a promising multiferroic material for versatile device applications due to its co-existence of magnetic (i.e., antiferromagnetic) and ferroelectric ordering at room temperature. While its functional properties have been extensively investigated, the exploration of its mechanical behavior was limited mostly to the thin-film form of BiFeO 3. In this work, we conducted in situ micropillar compression experiments to investigate the deformation behavior of La-doped BiFeO 3 (La-BFO) samples processed by both conventional and flash sintering methods. The conventionally sintered La-BFO exhibited limited deformability at room temperature and 450 °C. In contrast, the deformability of the flash-sintered La-BFO specimens was substantially improved by nearly 100% at both testing temperatures. Detailed post-mortem studies suggest that preexisting dislocations and wide anti-phase boundaries introduced during flash sintering can toughen flash-sintered La-BFO by easing dislocation migration and ferroelastic domain switching. This study provides a fresh perspective to design an advanced multifunctional system with improved mechanical properties. • Flash sintering introduced high population of pre-existing dislocations and anti-phase boundaries into La-BFO. • The flash sintered La-BFO deformed at room temperature exhibited an over 100% deformability enhancement. • At 450 °C, the flash-sintered La-BFO outperformed the conventionally sintered counterpart by showing plastic deformability. [ABSTRACT FROM AUTHOR]