Polarized small-angle neutron scattering studies of single-crystalline multiferroic BiFeO3 reveal a long-wavelength spin density wave generated by ∼1° spin canting of the spins out of the rotation plane of the antiferromagnetic cycloidal order. This signifies weak ferromagnetism within mesoscopic regions of dimension 0.03 microns along [11̄0], to several microns along , confirming a long-standing theoretical prediction. The average local magnetization is 0.06μB/Fe. Our results provide an indication of the intrinsic macroscopic magnetization to be expected in ferroelectric BiFeO3 thin films under strain, where the magnetic cycloid is suppressed.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy(all)