Fig. 4: Crystallographic origin of ferroelectricity in Y-rich YFO.
From: An antisite defect mechanism for room temperature ferroelectricity in orthoferrites
a, b Schematics of centrosymmetric Pbnm (a) and non-centrosymmetric R3c-like (b) structures. c Crystal structure and layer-resolved polarization for Y-rich YFO. Red columns indicate the atomic contribution to the ferroelectric polarization in Y-rich YFO calculated using the Born charge approximation, while blue columns show layer-resolved contributions to the ferroelectric polarization in stoichiometric YFO. d Ferroelectric polarization for various orthoferrites RFeO3 that are assumed to be epitaxially grown on SrTiO3 for all calculations with R/Fe = 1.28. e–g PACBED patterns including the simulated patterns, using the DFT relaxed centrosymmetric Pbnm (e) and non-centrosymmetric R3c (f) and the experimental result measured from the Y-rich YFO (α = 1.19) thin film sample (g). h Intensity profiles integrated across the pattern diagonals from PACBED patterns along the black arrows shown in e–g.
