The current paper presents a piezoelectric bimorph actuator produced by direct bonding of lithium niobate wafers with the mirrored Y and Z axes. Direct bonding technology allowed to fabricate bidomain plate with precise positioning of ideally flat domain boundary. By optimizing the cutting angle (128° Y-cut), the piezoelectric constant became as large as 27.3 pC/N. Investigation of voltage dependence of bending displacement confirmed that bimorph actuator has excellent linearity and hysteresis-free. Decrease of the applied voltage down to mV range showed the perfect linearity up to the sub-nm deflection amplitude. The frequency and temperature dependences of electromechanical transmission coefficient in wide temperature range (from 300 to 900 K) were investigated.

The analytical solution for the displacements of an anisotropic piezoelectric material in the uniform electric field is presented for practical use in the “global excitation mode” of piezoresponse force microscopy. The solution is given in the Wolfram Mathematica interactive program code, allowing the derivation of the expression of the piezoresponse both in cases of the anisotropic and isotropic elastic properties. The piezoresponse’s angular dependencies are analyzed using model lithium niobate and barium titanate single crystals as examples. The validity of the isotropic approximation is verified in comparison to the fully anisotropic solution. The approach developed in the paper is important for the quantitative measurements of the piezoelectric response in nanomaterials as well as for the development of novel piezoelectric materials for the sensors/actuators applications.

In this paper, we demonstrate how the experimentally observed nonmonotonic sideways motion of the plane domain wall in uniaxial ferroelectric, caused by the electric circuit feedback, can be described theoretically on the basis of the kinetic approach. We demonstrated experimentally the appearance of self-sustained periodic oscillations of the domain wall velocity and compared the theoretical results with the experimental data for switching in model ferroelectric stoichiometric lithium tantalate (LiTaO 3 ) produced by vapor transport equilibration (VTE-LT). Quasiperiodic and chaotic regimes of wall motion are predicted to be observed experimentally.

No abstract

The difference-frequency generation of terahertz (THz) radiation in single crystalline lithium niobate with periodic domain structure has been studied theoretically. The quadratic nonlinear dielectric with lithium niobate parameters has been considered in collinear geometry of wave interaction and absence of absorption for several types of the regular domain structures. The features of the generated THz and their dependence on the domain structure have been revealed.

No abstract

No abstract