Growth of lithium niobate crystals with a periodic domain structure by a modified zone melting method

Lithium niobate crystals with a periodic domain structure have been grown by a modified zone melting method. The size of grown crystals reaches 9 mm in diameter and up to 16 mm in length. It is found that the alternatively antiparalleled ferroelectric domains along the growth direction can be easily created in the crystals by a temperature modulation technique. The periods of the ferroelectric domain structures can be controlled to be 2.5-50 μm as revealed by optical microscopy. The method may provide a new route to grow large-size lithium niobate crystals with a periodic domain structure.