Probing of ferroelectric surface and bulk domains in RMnO3 (R=Y, Ho) by second harmonic generation -: art. no. 144102

Second harmonic generation (SHG) on ferroelectric 180degrees domains of YMnO3 and HoMnO3 reveals an order of magnitude increase of the SH intensity upon electric poling and distinct asymmetries of the intensity and phase of the SH signal with respect to the sign of the poling field. The effects are explained by a quantitative model for the interference of SH contributions from domains at the surface and in the bulk of the sample. On the basis of this model, the near-surface sensitivity of the SHG is employed to investigate the properties of a pinned ferroelectric surface layer inherent to the samples.