Large magnetic Bragg peak enhancement by ultrasound injection on FeTiO3

FeTiO3 is an ilmenite antiferromagnetic insulator containing Fe2+, with two-dimensional ferromagnetic honeycomb layers antiferromagnetically stacked along the c-axis. The magnetic Bragg peak intensity is found to be enhanced under the application of ultrasound up to 300% in FeTiO3 crystals at low temperatures. The pronounced enhancement is attributed to strong spin–lattice coupling of Fe2+ in FeTiO3. This effect disappears above 35 K, suggesting that the energy splitting of Fe2+ levels induced by spin–orbit coupling is about 35 K. This finding suggests a promising pathway toward high efficiency acoustic spin pumping.