Modelling of Cluster Formation in Optically Nonlinear Lithium Niobate Crystal

Modelling of qualitative processes at formation of energetically stable clusters of oxygen octahedrons in the ferroelectric phase of lithium niobate (LiNbO3) crystal is considered with respect to composition. The structure of clusters arranged along the direction of crystallographic axis Y is shown to be the most ordered. The least ordered structures occur in clusters arranged along Z axis in the direction of which the values of ratio R = Li/Nb are most scattered.