Extended Data Figure 3: Determination of polarization variants in BFO thin films.
From: Real-space imaging of non-collinear antiferromagnetic order with a single-spin magnetometer
a, Local out-of-plane PFM hysteresis loop with bias voltage. d33 is the out-of-plane piezoelectric coefficient. b, Homogeneous out-of-plane PFM phase corresponding to polarization variants pointing downward in a 6 μm × 6 μm area. c, In-plane PFM phase and d, amplitude for the cantilever parallel to [100]c. e, Sketch of the PFM cantilever and the four possible in-plane variants of polarization in BFO. f, Sketch of the [110]c direction of the cantilever, with the corresponding in-plane PFM amplitude (g) and phase (h). i, Sketch of the direction of the cantilever with the corresponding in-plane PFM amplitude (j) and phase (k). All the images in c to k have been acquired in the same 3 μm × 3 μm area.