Nanoscale measurement of ferroelectric domain wall strain and energy by near-field scanning optical microscopy

X-ray investigation of lateral hetero-structures of inversion domains in LiNbO3, KTiOPO4and KTiOAsO4

“…This is in agreement with the comparison of !-scan widths and integrated intensities taken on and off the grating, which all showed the grating peaks to be significantly broader and more intense, suggesting kinematical scatter from a damaged structure. The width of the 006 reflection in q z gave a strain distribution of Ád=d ¼ 2:0 Â 10 À4 on the grating, in direct agreement with Yang & Mohideen, who estimated a shear strain perpendicular to a domain wall in the LN analogue, LiTaO 3 , of 2 Â 10 À4 (Yang & Mohideen, 1998). The strain distribution on the grating appears confined to the direction normal to the domain walls, as 006 reflection profiles collected whilst scattering parallel to the domain walls displayed FWHMs unchanged from the untreated region, and only slightly higher diffracted intensities.…”

“…These corrugations also provide satellites with spacings of 1=Ã. Surface domain-wall thicknesses for LN and KTP of w = 0.15-15 mm (Yang & Mohideen, 1998;Kim et al, 2000;Wittborn et al, 2002) and 20-80 nm (Wittborn et al, 2002), respectively, have also been reported. The Malis-Gleiter model of a ferroelectric domain wall (Malis & Gleiter, 1976) supposes that the electric dipole rotates from P S to ÀP S over the domain-wall width, w, and so the structure factor in the region of this rotation, F rot , is assumed to be less than F H or F H , in the surrounding domains.…”

“…This is not, however, the only periodic feature that the PDI samples contain. PDI LN and KTP have been reported to have surface corrugation depths of Áz = 0.5-10 nm (Yang & Mohideen, 1998;Wittborn et al, 2002;Rommeveaux, 2002) and 2-30 nm (Wittborn et al, 2002;Rejmá nková et al, 2003), respectively. These corrugations also provide satellites with spacings of 1=Ã.…”

“…Thus, using the cross-hairs, the beam footprint was aligned on regions (Yang & Mohideen, 1998) ? to wall displaying good uniformity.…”

Combined excitation emission spectroscopy of defects for site-selective probing of ferroelectric domain inversion in lithium niobate

“…In contrast, intrinsic wall widths in LiNbO 3 measured with atomic force microscopy revealed a width of 150 nm [30] and the determined width with X-ray topography revealed p300 nm [31]. Using a near-field scanning optical microscope [32], birefringence in the vicinity of the domain wall in a distance of up to 1 mm was detected in LiTaO 3 (isostructural to LiNbO 3 ). These length scales were supported by recorded strain images with synchrotron radiation [33].…”