Browsing Zinātniskie raksti (CFI) / Scientific articles by Title
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Ultrafast Laser Writing in Different Types of Silica Glass
(Wiley, 2023)It is demonstrated that ultrafast laser writing in silica glass depends on the grade of silica glass associated with the method of its manufacture. Moreover, laser-written modifications, in particular birefringent ... -
Ultrafast luminescence of Ga- and In-doped ZnO ceramics
(Elsevier, 2021)In the presented work we compare luminescence characteristics of ZnO:Ga and ZnO:In ceramics prepared by hot uniaxial pressing method. Two types of initial powders were used. The first one was nanosized powder prepared by ... -
Ultraviolet Exposure Improves SERS Activity of Graphene-Coated Ag/ZrO2 Substrates
(MDPI, 2023)This study reveals a significant improvement in surface-enhanced Raman scattering (SERS) activity of Ag/ZrO2 substrates covered with a few-layer graphene preliminary exposed to ultraviolet (UV) light. The SERS-active ... -
Understanding of conversion process of magnetron deposited thin films of amorphous ReOx to crystalline ReO3 upon thermal annealing
(ACS Publications, 2020)Thin films of rhenium trioxide (ReO3) were produced by reactive DC magnetron sputtering from metallic rhenium target followed by annealing in the air in the range of temperatures from 200C to 350C. Nanocrystalline ... -
Unprecedented pressure-driven metallization and topological charge transport in an anion radical salt
(Elsevier, 2021)The hybrid inorganic/organic closed -stacking and soft lattice of a copper anion radial (Copper-7,7,8,8-tetracyanoquinodimethane) renders its electrical conductivity and structural modifications, which are susceptible to ... -
Unraveling the interlayer and intralayer coupling in two-dimensional layered MoS2 by X-ray absorption spectroscopy and ab initio molecular dynamics simulations
(Elsevier, 2023)Understanding interlayer and intralayer coupling in two-dimensional layered materials (2DLMs) has fundamental and echnological importance for their large-scale production, engineering heterostructures, and development of ... -
Unraveling the Structure and Properties of Layered and Mixed ReO3–WO3 Thin Films Deposited by Reactive DC Magnetron Sputtering
(American Chemical Society, 2022)Tungsten trioxide (WO3) is a well-known electrochromic material with a wide band gap, while rhenium trioxide (ReO3) is a “covalent metal” with an electrical conductivity comparable to that of pure metals. Since both WO3 ... -
Untangling the controversy on Ce3+luminescence in LaAlO3crystals
(Royal Society of Chemistry, 2022)Aluminum perovskites represent an important group of promising scintillation materials with excellent proportionality and energy resolution, but due to difficulties in crystal growth not much attention has been paid to ... -
Unveiling Molecular Changes in Water by Small Luminescent Nanoparticles
(Wiley-VCH Verlag, 2017)Nowadays a large variety of applications are based on solid nanoparticles dispersed in liquids—so called nanofluids. The interaction between the fluid and the nanoparticles plays a decisive role in the physical properties ... -
Up-conversion luminescence of GdVO4:Nd3+/Er3+ and GdVO4:Nd3+/Ho3+ T phosphors under 808 nm excitation
(Elsevier B.V., 2018)In recent years, there exists a tendency in research of up-conversion materials to shift excitation from 980 nm to shorter wavelengths. Here, in order to produce up-conversion luminescence emission of GdVO4-based materials ... -
Upconversion luminescence in transparent oxyfluoride glass ceramics containing hexagonal NaErF4
(Elsevier, 2019)Transparent oxyfluoride glass ceramics containing hexagonal NaErF4 nanocrystals were synthesized by a heat treatment of a precursor glass obtained by the melt quenching technique. Combined X-ray diffraction (XRD) and ... -
Upconversion luminescence in transparent oxyfluoride glass ceramics containing hexagonal NaErF4
(Elsevier B.V., 2019)Transparent oxyfluoride glass ceramics containing hexagonal NaErF4 nanocrystals were synthesized by a heat treatment of a precursor glass obtained by the melt quenching technique. Combined X-ray diffraction (XRD) and ... -
Upconversion luminescence of a transparent glass ceramics with hexagonal Na(Gd,Lu)F4 nanocrystals
(Elsevier B.V., 2017)Novel Er3+ doped transparent glass ceramics containing hexagonal Na(Gd,Lu)F4 nanocrystals were prepared from oxyfluoride glasses. The distribution of rare earth ions in the crystalline and glassy phase has been analyzed ... -
Upconversion luminescence of Er3 +/Yb3 + and their role in the stabilization of cubic NaLaF4 nanocrystals in transparent oxyfluoride glass ceramics
(Elsevier B.V., 2018)Novel Er3 + and Yb3 + doped transparent oxyfluoride glass ceramics containing NaLaF4 nanocrystals were prepared from oxyfluoride glasses with general composition of Na2O-NaF-LaF3-Al2O3-SiO2. The crystallization processes, ... -
Use of site symmetry in supercell models of defective crystals: Polarons in CeO2
(Royal Society of Chemistry, 2017)In supercell calculations of defective crystals, it is common to place a point defect or vacancy in the atomic position with the highest possible point symmetry. Then, the initial atomic structure is often arbitrary distorted ... -
UV light induced processes in pure and doped AlN ceramics
(Elsevier, 2021)AlN ceramics samples, pure and doped with Y2O3, Eu2O3 and GaN, and produced from the same AlN powder, were studied for photoelectric effect, photoluminescence spectra and kinetics and thermoluminescence under irradiation ... -
Vacancy defects in Ga2O3: First-principles calculations of electronic structure
(Multidisciplinary Digital Publishing Institute (MDPI), 2021)First-principles density functional theory (DFT) is employed to study the electronic structure of oxygen and gallium vacancies in monoclinic bulk β-Ga2 O3 crystals. Hybrid exchange– correlation functional B3LYP within the ... -
Variation of Nonlinear Refraction and Three-Photon Absorption of Indium–Tin Oxide Quantum Dot Thin Films and Solutions in Near Infrared Range
(MDPI, 2023)We characterize the nonlinear optical properties of indium–tin oxide (ITO) quantum dots (QDs) in the IR range using the Z-scan method. We present results of three-photon absorption (3PA), third harmonic generation (3HG), ... -
Vibrational analysis of paraelectric–ferroelectric transition of linbo3: An ab-initio quantum mechanical treatment
(MDPI, 2021)The phase transitions between paraelectric (PE) and ferroelectric (FE) isomorph phases of LiNbO3 have been investigated quantum mechanically by using a Gaussian-type basis set, the B3LYP hybrid functional and the CRYSTAL17 ... -
Water Splitting on Multifaceted SrTiO3 Nanocrystals: Calculations of Raman Vibrational Spectrum
(MDPI, 2022)Various photocatalysts are being currently studied with the aim of increasing the photocatalytic efficiency of water splitting for production of hydrogen as a fuel and oxygen as a medical gas. A noticeable increase of ...