Indication of room-temperature magnetodielectricity and weak spontaneous polarization in (Sr, Mn) co-doped La₂FeCrO6

Magnetic domain walls and disorders play an important role in controlling the properties of various magnetic materials, such as multiferroics. Here, the unusual role of disorder in exhibiting intriguing properties within the double perovskite system La₂FeCrO₆is reported. It is suggested that controlling certain disorders inherent to double perovskite systems, such as anti-site disorder (ASD) in La₂FeCrO₆, may stabilize an anti-phase boundary (APB) between two different domains. This anticipated ASD, along with the APB and lattice contraction, leads to intriguing behaviors, such as negative magnetization, magnetization reversal, magnetodielectricity, spin-phonon coupling, and possible spontaneous polarization. While the very small volume fraction of such site disorders and domain walls-comparable to other low-volume fraction extrinsic effects-makes it challenging to confirm their existence, this study offers a plausible and unconventional approach to controlling such disorder to achieve room-temperature magnetodielectricity and possible spontaneous polarization, encouraging further exploration of room-temperature ferroicities in different systems.