Photoelectric fields in doped lithium niobate crystals

Photoinduced light scattering (PILS) in nominally pure stoichiometric and congruent lithium niobate single crystals (LiNbO3), and ones doped with B³⁺, Cu²⁺, Zn²⁺, Mg²⁺, Gd³⁺, Y³⁺, Er³⁺ cations was studied. All crystals have a relatively low effect of photorefraction and are promising materials for frequency conversion, electro-optical modulators and shutters. It was found that the photovoltaic and diffusion fields for some crystals have a maximum at a wavelength of 514.5 nm. All the crystals studied are characterized by a maximum of the integral intensity of the speckle structure of the PILS at a wavelength of 514.5 nm.Institute of Solid State Physics, University of Latvia as the Center of Excellence has received funding from the European Union’s Horizon 2020 Framework Programme H2020-WIDESPREAD-01-2016-2017-TeamingPhase2 under grant agreement No. 739508, project CAMART

Photoelectric Fields and Band Gap in Doped Lithium Niobate Crystals

Photorefractive effect was researched and band gap was determined in nominally pure congruent and stoichiometric lithium niobate crystals, and in a series of congruent LiNbO3 crystals doped by Mg, Zn, B, Gd, Y, Er cations, and LiNbO3 single crystals with double doping Mg:Gd, Mg:Fe, Mg:Y, Mg:Ta by photoinduced light scattering and optical spectroscopy methods. Keywords: lithium niobate single crystal, doping, photorefractive effect, photoinduced light scattering, optical spectroscopy, band ga

Fractal micro- and nanostructures and their influence on significant properties of crystalline and ceramic oxide compounds of niobium and tantalum

Исследованы процессы образования периодических микро- и наноструктур фрактального типа при неравновесной кристаллизации кристаллов ниобата лития и обработке керамик Ta2O5 и Nb2O5 концентрированными световыми потоками во взаимосвязи с формированием принципиально новых физических характеристик.The formation of periodic fractal micro- and nanostructures were studied at nonequilibrium crystallization of lithium niobate crystals and treatment of Ta2O5 and Nb2O5 ceramics by focused light beam in correlation with appearance of qualitatively new physical characteristics

The temperature evolution of the domain structure and the spontaneous unipolarity of strongly doped LiNbO3:Zn crystals

В исходно полидоменных и монодоменизированных кристаллах LiN O3:Zn в результате высокотемпературного отжига в условиях короткого замыкания обнаружено существенное увеличение униполярности. Эффект сопровождается проявлением диэлектрической дисперсии и аномалиями на температурных зависимостях проводимости ζ(Т) и диэлектрической проницаемости ε(Т).Rise in unipolarity were detected in originally polydomain and turned to single domain state LiNbO3:Zn crystals as the result of high temperature annealing in short-circuit conditions. The effect is accompanied y the appearance of dielectric disperse and anomalies on ζ(Т) and ε(Т)