The droplet generation under the action of the pyroelectric field created by uniform heating or cooling of the monodomain lithium tantalate plate was studied. The droplets of dielectric and conductive liquid with the volume below picoliter have been deposited on glass substrate with good reproducibility. It was shown that the drying of the dispensed colloid droplets allowed producing the uniform circular and ring-like micron-size patterns of Ag nanoparticles on the substrate. The numerical simulation of attractive force induced by pyroelectric field which is applied to the drop allowed us to explain the obtained results.

The active substrates with rings of silver nanoparticles arising by drying of sessile colloid drops were used for realization of the surface-enhanced Raman scattering. The colloids have been produced by laser ablation in water using pulse Yb fiber laser. The droplets with diameter down to 10 mu m were dispensed by electrohydrodynamic technique by means of pyroelectric field produced by lithium tantalate plate. The optimal spatial distribution of hotspots was obtained for substrate covered by the micron-size rings of silver nanoparticles. The method was applied for various organic molecules rhodamine 6G, thymine, and RNA with enhancement factor up to 10(5).

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 influence of the artificial surface layer (photoresist film) on the domain kinetics was studied in congruent lithium niobate single crystals. The switching current data was fitted by modified Kolmogorov-Avrami formula. The qualitative change of the domain structure evolution for photoresist film thickness above 2 mu m was revealed by in situ optical visualization and analysis of the switching current data. The linear dependence of the threshold field increase on the film thickness was found. The quasi-regular nanodomain structures on Z+ polar surface were studied by scanning probe and Raman confocal microscopy and the domain evolution scenario was revealed.

ФЦП «Исследования и разработки по приоритетным направлениям развития научно-технологического комплекса России на 2007-2013 годы»