Structural origin of room-temperature ferroelectricity in spark-plasma sintered DyCrO3 and LaCrO3

Identification of novel multiferroic materials with high-ordering temperatures remains at the forefront of condensed matter physics research. Recently, room-temperature ferroelectricity of structural origin, arising from off-centering displacements of Gd and Cr ions, has been identified in spark-plasma sintered (SPS) GdCrO₃ [Suryakanta Mishra et al., Phys. Rev. B 104, L180101 (2021), 10.1103/PhysRevB.104.L180101]. Here, using a similar synthesis protocol (involving SPS), we have been able to engineer room-temperature ferroelectricity (FE) from a similar mechanism in two otherwise nonferroelectric R CrO₃ (R= rare-earth) compounds, namely, DyCrO₃ (which is reported as a quantum paraelectric) and LaCrO₃ (which is already known to be paraelectric). Room-temperature FE in SPS-LaCrO₃ and SPS-DyCrO₃ is confirmed through various electrical, calorimetric, and synchrotron-based structural investigations. Out of these two emergent room-temperature FE materials, SPS-LaCrO₃ also undergoes a high-temperature antiferromagnetic ordering at 290 K, thus coming very close to becoming the first room-temperature multiferroic material in this promising family of R CrO₃ compounds.