Introduction:
Within the framework of the phenomenological theory of phase transitions of
the second kind of Ginzburg-Landau, the kinetics of ordering of a rapidly quenched highly nonequilibrium
domain structure is considered using the lithium tantalate and lithium niobate crystals as an example.
Experimental:
Using the statistical approach, evolution equations describing the formation of the domain
structure under the influence of a high-frequency alternating electric field in the form of a standing
wave were obtained. Numerical analysis has shown the possibility of forming thermodynamically
stable mono- and polydomain structures. It turned out that the process of relaxation of the system to
the state of thermodynamic equilibrium can proceed directly or with the formation of intermediate
quasi-stationary polydomain asymmetric phases.
Results:
It is shown that the formation of Regular Domain Structures (RDS) is of a threshold character
and occurs under the influence of an alternating electric field with an amplitude less than the critical
value, whose value depends on the field frequency. The conditions for the formation of RDSs with a
micrometer spatial scale were determined.
Conclusion:
As shown by numerical studies, the RDSs obtained retain their stability, i.e. do not disappear
even after turning off the external electric field. Qualitative analysis using lithium niobate crystals
as an example has shown the possibility of RDSs formation in high-frequency fields with small amplitude
under resonance conditions
Highly efficient generation of 02 mJ terahertz pulses in lithium niobate at room temperature with sub-50 fs chirped Ti:sapphire laser pulses
