Experimental evidence of domain wall tilting in periodically poled lithium niobate crystals grown by the Czochralski off-center technique

Periodically poled lithium niobate crystals are expected to have ferroelectric domain boundaries parallel to the direction of the spontaneous polarization. The authors report, however, that this is not the case for periodic structures grown by the off-center Czochralski technique. By exploiting the high resolution x-ray diffraction technique in reciprocal space mapping mode, the authors demonstrate that the angle between the domain border and the spontaneous polarization directions is different from zero, reaching a value as high as 5°.