Li+, Vo superjonikų struktūros, elementinės sudėties ir krūvininkų pernašos sąsajų tyrimas

The influence of the structure and elemental composition of lithium ions’ and oxygen vacancies’ (Vo) solid electrolytes (SE) on their electrical properties are investigated in the dissertation. The technological conditions of SE ceramics’ and films’ fabrication, which influence their microstructure, are described. The results of the investigation of the surfaces, temperature stability, and electrical properties are presented. Li+ SE belong to monoclinic, orthorhombic, or rhombohedral symmetries. The microstructure of the ceramics is mainly influenced by the temperature of their sintering. It has been shown by XPS that LiCe2/3PO4 ceramic is Li+-ion conductor. Complex impedance spectroscopy investigation showed that the increase of x in the systems Li1+xScxZr2-x(PO4)3, Li1+xZr2-2xAlxTix(PO4)3, and Li1+xGe2-2xAlxTix(PO4)3 (where x = 0.1, 0.2, 0.3) leads to the increase of bulk ionic conductivity of the ceramics and to the decrease of its activation energy. Phase transition temperature in Li3Sc2–xBx(PO4)3 compounds depends on x. The anomalies of temperature dependencies of bulk conductivity of Li3-xSc2-x-yYyZrx(PO4)3 system were observed when x = 0.1, y = 0, 0.1. The anomalies are related to superionic phase transitions in the materials, but no phase transitions have been detected for x = 0.2 compound in the studied temperature range. Ionic conductivity and its activation energy of YSZ thick films prepared by magnetron sputtering depend on their preparation’s technological conditions. Higher annealing temperature of NiO-CGO films prepared by spray pyrolysis causes bigger crystallites and higher polarization resistance of the film. Dielectric permittivity of Li+ SE ceramics and YSZ thick films increases with increase of temperature

Investigation of the Correlation between Structure, Elemental Composition, and Charge Carriers’ Transport in Li+, Vo Solid Electrolytes

The influence of the structure and elemental composition of lithium ions’ and oxygen vacancies’ (Vo) solid electrolytes (SE) on their electrical properties are investigated in the dissertation. The technological conditions of SE ceramics’ and films’ fabrication, which influence their microstructure, are described. The results of the investigation of the surfaces, temperature stability, and electrical properties are presented. Li+ SE belong to monoclinic, orthorhombic, or rhombohedral symmetries. The microstructure of the ceramics is mainly influenced by the temperature of their sintering. It has been shown by XPS that LiCe2/3PO4 ceramic is Li+-ion conductor. Complex impedance spectroscopy investigation showed that the increase of x in the systems Li1+xScxZr2-x(PO4)3, Li1+xZr2-2xAlxTix(PO4)3, and Li1+xGe2-2xAlxTix(PO4)3 (where x = 0.1, 0.2, 0.3) leads to the increase of bulk ionic conductivity of the ceramics and to the decrease of its activation energy. Phase transition temperature in Li3Sc2–xBx(PO4)3 compounds depends on x. The anomalies of temperature dependencies of bulk conductivity of Li3-xSc2-x-yYyZrx(PO4)3 system were observed when x = 0.1, y = 0, 0.1. The anomalies are related to superionic phase transitions in the materials, but no phase transitions have been detected for x = 0.2 compound in the studied temperature range. Ionic conductivity and its activation energy of YSZ thick films prepared by magnetron sputtering depend on their preparation’s technological conditions. Higher annealing temperature of NiO-CGO films prepared by spray pyrolysis causes bigger crystallites and higher polarization resistance of the film. Dielectric permittivity of Li+ SE ceramics and YSZ thick films increases with increase of temperature

NMR Investigations in Li 1.3 Al 0.3 Ti 1.7 (PO 4 ) 3 Ceramics Part III: Local Dynamical Aspect Seen from Aluminum and Phosphorus Sites

International audienc

Microscopic model of intergrain boundary junction

The statistical mechanics differential-difference equations for the ions concentration distribution that account for the diffusion, electrical conductivity and Poisson contributions are derived. They represent differential-difference analogues of the phenomenological continuity equations for the ions. Spatial inhomogeneities (grain interiors, grain boundaries, intergrain regions, etc.) can easily be taken into account by proper adjusting the system material parameters (diffusion coefficients or particle transition rates, electric conductivities, thermodynamic factors or chemical capacitances). The solution of the equations allows investigating impedance spectra of inhomogeneous systems, e. g. electro-conducting ceramics. The results can be used for interpretation of experimental impedance spectra and evaluation of the medium transport characteristics. A simple example of the intergrain boundary junction is considered

NMR Investigations in Li 1.3 Al 0.3 Ti 1.7 (PO 4 ) 3 Ceramics. Part I: Structural Aspect

International audienc

Formation and characteristics of thin films of ZrO2-8 mol % Y2O3 solid electrolytes

[6th International Conference on Self-Formation Theory and Applications Vilnius, Lithuania, Nov. 26-28, 2003]Thin films of ZrO2-8mol % Y2O3 have been deposed by pulsed DC magnetron sputtering method. The substrates of Ni-cermet and alloy-600 for the films were used. The results of the investigation of the X-ray diffraction patterns and SEM showed that the films are nanocrystalline and belong to cubic symmetry. The relaxation process is related to the ion transport in thin films. The results of the investigation of the temperature dependencies of thin films ionic conductivity showed that the dependence (T) is caused by the temperature dependence of oxygen vacancy mobility, while the number of charge carriers remains constant with temperatureLietuvos energetikos institutas, [email protected] universitetasVilniaus universitetas, [email protected] universitetas, [email protected] Didžiojo universiteta

Zr2-8 mol.% Y2O3 plonųjų sluoksnių gamybos technologija ir jų elektrinės savybės

Pateiktos ZrO2-8 mol.% Y2O3 plonųjų sluoksnių gamybos technologinės sąlygos, naudojant impulsinį magnetroną, o taip pat aprašyti sluoksnių joninio laidumo sando temperatūriniai ir dažniniai tyrimai. Elektriniai matavimai atlikti 300-1000 K temperatūrų intervale ir 2 10(4)-10(6) Hz dažnių diapazone. Plonųjų sluoksnių nusodinimas vyko 0,25-1,8 Pa slėgio O2 dujose. Sluoksniai buvo formuojami ant lydinio 600 bei 5 sv.% CSY/95 sv.% NiO padėklų. Kintamajame 2 10(4)-10(6) Hz dažnių elektriniame lauke aptikta relaksacinė elektrinių parametrų dispersija, kuri siejama su VO-- pernaša plonuosiuose sluoksniuose. Parodyta, kad temperatūrinį kristalitinio laidžio kitimą daugiausia lemia VO- krūvininkų judrio temperatūrinis kitimasThin films of ZrO2-8 mol.% Y2O3 have been deposed by pulsed magnetron sputtering on Ni-cermet and alloy-600 substrates. Investigation of the X-ray diffraction patterns and SEM has shown that the films are polycrystalline and belong to cubic symmetry. The relaxation process is related to the ion transport in thin films. Investigation of the temperature dependences of thin film ionic conductivity [sigma] has shown that the dependence [sigma](T) is caused by the temperature dependence of oxygen vacancy mobilityLietuvos energetikos institutas, [email protected] universitetasVytauto Didžiojo universiteta

Anomalous temperature-dependent electrical properties of Na 2 MnP 2 O 7

International audienc