Significance and value of lithium niobate crystal research: Lithium niobate crystal is a collection of light, birefringence, acousto-optics, nonlinear optics, photoelasticity, piezoelectric, photorefractive, pyroelectric, ferroelectric and photovoltaic Intraocular lens materials, such as the impact effect, have been favored by people for many years. It is widely used in integrated light and optical waveguides, such as optical amplifier modulators, second harmonic generators, Q-switches, beam redirectors, phase connectors, dielectric waveguides, storage elements, holographic (optical) data processing devices, etc. Lithium niobate crystal is a ferroelectric phase at room temperature, and a paraelectric phase when the temperature is higher than the local temperature.

The crystal structure of lithium niobate crystal: Lithium niobate crystal has a ferroelectric phase and a paraelectric phase structure. The paraelectric phase space group is R3-C, and the ferroelectric phase space group is R3C, which is a hexagonal unit cell. In lithium niobate crystals, oxygen atoms form oxygen octahedrons, and the oxygen octahedrons are stacked in a coplanar form to form a stack, and the common plane is perpendicular to the triple axis of the oxygen octahedron. Many stacks are then connected in the form of common edges to form crystals. In the paraelectric phase, the oxygen octahedrons in each stack alternately appear in the following order: one oxygen octahedron with Nb in the center, two oxygen octahedrons with Li on their common surface, in the octahedral gap, One third is occupied by Li atoms, one third is Nb, and one third is hole. Along the C axis, the order of the atoms is as follows: Nb, holes, Li, Nb, holes, Li, ... In the ferroelectric phase, both Li and Nb are displaced along the C axis, and electricity is generated on the C axis. Dipole moment, that is, spontaneous polarization appears.