Giant electric field-controlled magnetism in Bi0.86Sm0.14FeO3 multiferroic ceramics with Pna21 symmetry

In the present work, Bi0.86Sm0.14FeO3 ceramics with near Pna2(1) single-phase structure were obtained by a repeated longtime sintering process, and the dielectric, ferroelectric, and magnetic characteristics were determined together with the magnetoelectric coupling coefficient. The evolution of Pna2(1) symmetry was revealed by transmission electron microscope analysis, and the ferroelectric transition from Pbnm to Pna2(1) was determined by differential scanning calorimetry analysis together with the dielectric characterization, and the Curie temperature was determined as 195 degrees C. The saturated polarization-electric field (P-E) hysteresis loop was obtained with P-r = 12.2 mu C cm(-2), and the unlocking of ferromagnetism was confirmed by the apparent magnetization-magnetic field (M-H) hysteresis loop with M-r = 77.4 emu mol(-1). The giant electric field-controlled magnetism was due to the Pna2(1)/R3c field-induced transition, which was confirmed by both structure analysis and theoretical calculation, and the change of remanent magnetization under an electric field was achieved up to 44.8 emu mol(-1) (57.9%), which was much bigger than that of rare-earth (RE)-substituted BiFeO3 ceramics without optimizing Pna2(1) phase fraction. The present results might significantly deepen the physical understanding of Pna2(1) phase and subsequently provide new hints on further enhancing electric field-controlled magnetism in RE-substituted BiFeO3 multiferroic ceramics.

Automated summary

This study obtained Bi0.86Sm0.14FeO3 ceramics with near Pna2(1) single-phase structure through a repeated longtime sintering process. The evolution of Pna2(1) symmetry, ferroelectric transition, and magnetoelectric coupling were determined, revealing a giant electric field-controlled magnetism effect. The results deepen the understanding of Pna2(1) phase and offer insights for enhancing electric field-controlled magnetism in RE-substituted BiFeO3 multiferroic ceramics.