Spontaneous polarization reversal and photorefractive effect in single-domain iron-doped lithium niobate crystals

Partial reversal of spontaneous polarization in iron-doped LiNbO3 crystals takes place at room temperature in an external field of 104 V cm−1, as proved by the Barkhausen effect. Similarly, the formation of an internal photorefractive field of 104 V cm−1 leads to partial ferroelectric switching in the illuminated region of crystal. The dependences of the number of Barkhausen jumps on the external and internal fields are in close agreement.