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Search results for: strontium doped titanates
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Ion conduction in beryllium-alumino-silicate glasses doped with sodium or sodium and lithium ions
PublicationElectrical properties of beryllium-alumino-silicate glasses containing sodium ions or sodium and lithium ions were studied with impedance spectroscopy technique over a frequency range from 10 mHz to 1 MHz and at temperature range from 213 to 473 K. The frequency- and temperature-dependent conductivity spectra of individual single alkali glasses were superimposed by means of the Summerfield scaling. Mixed-alkali glasses do not overlap...
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Electrochemical oxidation of sulphamerazine at boron-doped diamond electrodes: Influence of boron concentration
PublicationThe boron-doped diamond (BDD) electrodes with different boron concentrations have been tested as electrode material for sulphamerazine (SRM) oxidation in water solution. An investigation of the electrode morphology and molecular structure was carried out using high resolution scanning electron microscopy (SEM) and Raman spectroscopy. Electrochemical results showed clearly that the kinetics and efficiency of SRM oxidation were dependent...
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Investigation of praseodymium and samarium co-doped ceria as an anode catalyst for DIR-SOFC fueled by biogas
PublicationThe Pr and Sm co-doped ceria (with up to 20 mol.% of dopants) compounds were examined as catalytic layers on the surface of SOFC anode directly fed by biogas to increase a lifetime and the efficiency of commercially available DIR-SOFC without the usage of an external reformer. The XRD, SEM and EDX methods were used to investigate the structural properties and the composition of fabricated materials. Furthermore, the electrical...
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Structural and luminescence properties of B2O3-Bi2O3-AlF3 glass doped with Eu3+, Tb3+ and Tm3+ ions
PublicationThe B2O3-Bi2O3-AlF3 glass system doped with Eu3+, Tb3+, Tm3+ and triply doped with Eu3+/Tm3+/Tb3+ ions in different molar ratios were successfully synthesized. Glass transition and crystallization temperatures were examined by Differential Scanning Calorimetry (DSC) measurements. X-ray Diffraction (XRD) confirmed the amorphous character of the samples. Fourier Transform Infrared Spectroscopy (FTIR) revealed that the glass matrix...
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The interplay between dopant and a surface structure of the photocatalyst – The case study of Nb-doped faceted TiO2
PublicationAnatase nanoparticles, exposing the majority of the {0 0 1}, {1 0 0} and {1 0 1} facets were synthesized and doped with different niobium amount to investigate the self-trapping of the excess electrons and resulting photocatalytic activity. Photocatalyst structure and presence of excess electrons inside the obtained Nb-doped anatase samples was confirmed by the combination of structural and spectroscopic analyses. Only for the...
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Nitrogen-doped diamond thin films: potential application in Fabry-Pérot interferometer
PublicationIn this paper we present results of preliminary research of using nitrogen-doped diamond (NDD) films as reflective layer in Fabry-Pérot interferometer. NDD films were deposited on Si substrates by Microwave Plasma Enhanced Chemical Vapor Deposition (MPECVD) with the use of CH4, H2 and N2 gas mixtures. During deposition process methane flow rate varied while nitrogen flow was constant. We performed series of measurements which showed...
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The electrical, morphological and optical properties of heavily boron-doped diamond sheets as a function of methane concentration in the gas phase
PublicationBoron-doped diamonds (BDD) are known for their excellent properties such as high thermal conductivity, high mobility, low absorption in visible light, and biocompatibility. In this work, we investigated the electrical, morphological and optical properties of heavily boron-doped diamond thin sheets as a function of methane concentration in the gas phase. Free-standing diamond sheets were fabricated using a microwave plasma-assisted...
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Applying of Doped Graphene Oxide Coatings for Corrosion Prevention
PublicationINTRODUCTION Graphene is a carbonaceous material characterized by extraordinary properties (high electron mobility, high surface area, high mechanical strength of 1100 GPa, very dense network hindering the passage of even the smallest helium atoms) [1]. Therefore, it found many applications, also as an anti-corrosive layer [2]. Electrophoretic Deposition (EPD) is one of the methods to deposit coatings. However, due to slight solubility...
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Amperometric sensing of chemical oxygen demand at glassy carbon and silicon electrodes modified with boron-doped diamond
Publication.A boron-doped diamond (BDD) sensor is proposed for effective detection of chemical oxygen demand (COD) by means of amperometric technique. Boron-doped diamond thin films, acting as active sensors, were deposited on both silicon wafer and glassy carbon (GC) substrates by microwave plasma assisted chemical vapour deposition. SEM micrographs showed that BDD–Si displays triangle-faceted crystallites ca. 0.5–3 μm in size, while BDD–GC...
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Conductive printable electrodes tuned by boron-doped nanodiamond foil additives for nitroexplosive detection
PublicationAn efficient additive manufacturing-based composite material fabrication for electrochemical applications is reported. The composite is composed of commercially available graphene-doped polylactide acid (G-PLA) 3D printouts and surface- functionalized with nanocrystalline boron-doped diamond foil (NDF) additives. The NDFs were synthesized on a tantalum substrate and transferred to the 3D-printout surface at 200 °C. No other electrode...
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Gigantic electro-chemo-mechanical properties of nanostructured praseodymium doped ceria
PublicationSome oxygen defective fluorites are non-Newnham electrostrictors, i.e., the electromechanical response does not depend on their dielectric properties. Here, we show gigantic electrostriction in nanocrystalline 25 mol% praseodymium doped ceria (PCO) bulk ceramics. The material was fabricated with a fieldassisted spark plasma sintering (SPS) process from high-purity nanoscale PCO powders (<20 nm). The SPS process consolidates the...
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Optimizing Ni–Cr patterned boron-doped diamond band electrodes: Doping effects on electrochemical efficiency and posaconazole sensing performance
PublicationThere is growing interest in developing diamond electrodes with defined geometries such as, for example, micrometer-sized electrode arrays to acquire signals for electroanalysis. For electroanalytical sensing applications, it is essential to achieve precise conductive patterns on the insulating surface. This work provides a novel approach to boron-doped diamond patterning using nichrome masking for selective seeding on an oxidized...
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Tunable emission and energy transfer of B2O3–Bi2O3–AlF3 glass system doped with Eu3+/Dy3+
PublicationThe structure and luminescent properties of the B2O3–Bi2O–AlF3 glass system doped with Eu3+/Dy3+ ions in different molar ratios were studied. A series of glasses were synthesized by the conventional melt quenching technique. Glass transition and crystallization temperatures were examined by Differential Thermal Analysis (DTA) measurements. The amorphous character of the prepared samples was confirmed by the X-ray diffraction (XRD)...
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Non-toxic fluorine-doped TiO2 nanocrystals from TiOF2 for facet-dependent naproxen degradation
PublicationIn the present study, the photocatalytic degradation of naproxen (NPX), which is a nonsteroidal anti-inflammatory drug (NSAID), frequently detected in drinking water, was investigated. The F-doped TiO2 with defined morphology was successfully obtained from TiOF2 and applied for photocatalytic degradation under UV-vis and visible light. All samples were characterised by X-ray diffraction, scanning electron microscopy, X-ray photoelectron...
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Electrical properties of Na2O-CaO-P2O5 glasses doped with SiO2 and Si3N4
PublicationSodium-calcium-phosphate glasses doped with SiO2 or Si3N4 having similar sodium ion concentrations were prepared by melt quenching. The conductivity was measured by impedance spectroscopy under nitrogen atmosphere in a wide frequency range (10 mHz–1 MHz) and wide temperature range (153–473 K). At 36.6 °C, DC conductivities of all glasses vary between 1.1 ∗ 10−12 and 8.9 ∗ 10−12 S cm−1 and have similar activation energies (between...
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Heterogeneous distribution of surface electrochemical activity in polycrystalline highly boron-doped diamond electrodes under deep anodic polarization
PublicationThe surface homogeneity of boron-doped diamond electrodes is variable and depends on anodic polarization conditions. The differentiation factor is the gradual and localized change in surface termination. A series of measurements under different polarization conditions was performed in order to investigate the scale of this effect. Nanoscale impedance microscopy (NIM) revealed large variation of surface resistance in individual...
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High temperature monoclinic-to-tetragonal phase transition in magnesium doped lanthanum ortho-niobate
PublicationMagnesium doped lanthanum ortho-niobate (La0.98Mg0.02NbO4) was prepared by the molten salt synthesis method. X-ray diffraction and dilatometry methods were used to study high temperature behavior of the ceramic material. Special attention was paid to the phase transition between the monoclinic and tetragonal phases. The values of spontaneous strain on the basis of unit cell parameter, obtained by Rietveld refinement, have been...
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Urchin-like TiO2 structures decorated with lanthanide-doped Bi2S3 quantum dots to boost hydrogen photogeneration performance
PublicationThe formation of heterojunctions between wide- and narrow-bandgap photocatalysts is commonly employed to boost the efficiency of photocatalytic hydrogen generation. Herein, the photoactivity of urchin-like rutile particles is increased by decorating with pristine as well as Er- or Yb-doped Bi2S3 quantum dots (QDs) at varied QD loadings (1–20 wt%) and doping degrees (1–15 mol%), and the best hydrogen evolution performance is achieved at...
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Nano - and microcrystals of doped niobates
PublicationPublikacja przedstawia wyniki analizy pomiarów wysokotemperaturowej rentgenografii strukturalnej niobanu lantanu domieszkowanego magnezem.
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Melamine-modified boron-doped diamond towards enhanced detection of adenine, guanine and caffeine
PublicationThis work describes the electrochemical method of boron-doped diamond (BDD) modification by poly-melamine to obtain organic film. The detection of adenine, guanine and caffeine were carried out by differential pulse wave voltammetry. The poly-melamine modified B-NCD electrodes exhibit excellent activity towards the electrochemical oxidation of all examined analytes. The poly-melamine modified BDD electrodes in all measurements...
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Electrical conductivity of nanostructured acceptor-doped ceria fabricated by spark plasma sintering (SPS)
PublicationHigh purity nanoscale powders (~10–15 nm size) of two different compositions of ceria, doped with Gd3+ and Ca2+, have been consolidated by spark plasma sintering (SPS) at different temperatures. Fully-dense samples were observed only at a sintering temperature of 980 °C. The as-sintered samples showed rather fast grain growth with an average grain size below 300 nm. The electrical properties of the samples were evaluated by impedance...
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Determination of the ionic conductivity of Sr-doped lanthanum manganite by modified Hebb–Wagner technique
PublicationThe Hebb–Wagne rpolarization method with the electron blocking electrode has been discussed in this paper in aim to determine a partial ionic conductivity of Sr-doped lanthanum manganite.The “limiting current” in the proposed system was measured using the two-point DC technique with additional Pt electrode between LSM and blocking electrode.The electrochemical model based on bulk diffusion processes and Boltzmann statistics has...
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Boron-Doped Diamond/GaN Heterojunction—The Influence of the Low-Temperature Deposition
PublicationWe report a method of growing a boron-doped diamond film by plasma-assisted chemical vapour deposition utilizing a pre-treatment of GaN substrate to give a high density of nucleation. CVD diamond was deposited on GaN substrate grown epitaxially via the molecular-beam epitaxy process. To obtain a continuous diamond film with the presence of well-developed grains, the GaN substrates are exposed to hydrogen plasma prior to deposition....
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Two kinds of oxygen vacancies in lithium titaniate doped with copper as detected by EPR
PublicationLithium titanate (Li1+xTi2-xO4) doped with Cu2+ ions was synthesized by sol-gel processing method. The structure and morphology are characterized by X-ray Diffraction (XRD), X-ray Photoemission Spectroscopy (XPS), Scanning Electron Microscopy (SEM) and Electron Paramagnetic Resonance (EPR). Spin Hamiltonian parameters describing Zeeman and hyperfine interaction for 63Cu2+ ions were obtained from EPR spectra simulations. The spectra...
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Fabrication and characterization of composite TiO2 nanotubes/ boron-doped diamond electrodes towards enhanced supercapacitors
PublicationThe composite TiO2 nanotubes / boron-doped diamond electrodes were deposited using Microwave Plasma Enhanced Chemical Vapor Deposition resulting in the improved electrochemical performance. This composite electrode can deliver high specific capacitance of 7.46 mF cm‐− 2 comparing to boron-doped diamond (BDD) deposited onto flat Ti plate (0.11 mF cm‐− 2).The morphology and composition of composite electrode were characterized...
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Electrochemical oxidation of PFOA and PFOS in landfill leachates at low and highly boron-doped diamond electrodes
PublicationPolyfluorinated alkyl substances (PFASs) may reach landfill leachates (LLs) due to improper waste management. In this study perfluorooctanoate (PFOA) and perfluorooctane sulphonate (PFOS) were used as representatives of PFASs in the decomposition on boron-doped diamond electrodes (BDDs) with high (10k ppm) and low (0.5k ppm) boron doping concentrations. The result shows that although better COD removal efficacies are obtained on...
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Direct amination of boron-doped diamond by plasma polymerized allylamine film
PublicationA novel microwave pulsed-plasma based method for the modification of the hydrogen-terminated polycrystalline boron-doped diamond (BDD) with a thin film of polymerized allylamine (PPAAm) is reported. A modified BDD surface is resistant to hydrolysis and delamination and is characterized by a high density of positively charged amino groups. Pulsed microwave plasma was applied to improve the degree of cross-linking and bonding of...
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Elucidating photoluminescent properties of Eu‐doped Ca–Al–Si–O(–N) glasses and the local structures of Eu ions
PublicationEuropium (Eu) ion–doped luminescent materials have attracted considerable attention for their numerous optical applications. Eu-doped Ca–Al–Si–O(–N) glasses were synthesized from a mixture of oxynitride glasses and Eu2O3 powder using a standard melt-quenching technique in a radiofrequency furnace. The source Eu trivalent ions primarily changed to Eu2+ during melting, and the ratio of Eu2+ ions increased with an increase in Eu content...
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Electrical properties of A-site Ca-doped LaNb1-xAsxO4-δ ceramics
PublicationThe electrical properties of A-site Ca-doped LaNbO4 with the addition of As in the B-site, have been investigated. Total, grain- and specific grain boundary electric conductivities in different oxygen partial pressure, and water vapour partial pressure were determined. Additional conductivity measurements were performed in nitrogen, to suppress the possible p-type conductivity, focusing on protonic conductivity. The maximum measured...
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Iron doped manganese cobaltite spinel coatings produced by electrophoretic co-deposition on interconnects for solid oxide cells: Microstructural and electrical characterization
PublicationWe report a systematic microstructural and electrical characterization of iron doped Mn–Co spinel coatings processed by electrophoretic co-deposition of Mn1.5Co1.5O4 and Fe2O3 powders on Crofer 22 APU and AISI 441 steel substrates. Iron addition to Mn–Co spinel coating leads to a reduction of the area specific resistance on both substrates, after 3200 h at 750 °C. The Fe doped Mn–Co coating both leads to a thinner oxide scale and...
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Enhanced capacitance of composite TiO2 nanotube / boron-doped diamond electrodes studied by impedance spectroscopy
PublicationWe report on the novel composite nanostructures based on boron-doped diamond thin film grown on top of TiO2 nanotubes. The nanostructures made of BDD-modified titania nanotubes showed an increase in activity and performance when used as electrodes in electrochemical environments. The BDD thin films (~200-500 nm) were deposited using microwave plasma assisted chemical vapor deposition (MW PA CVD) onto anodically fabricated TiO2...
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Two-step synthesis of niobium doped Na–Ca–(Mg)–P–Si–O glasses
PublicationNiobium doped biosolubility glasses in the Na–Ca–(Mg)–P–Si–O system were prepared by using an untypical two-step synthesis route. The parent glass was melted in air atmosphere at 1350 °C followed by re-melting the glass in Nb crucible with the addition of metallic Mg/Ca powder in the nitrogen atmosphere. The second melting step was carried out at 1450–1650 °C, using an induction furnace. The topography and structure of the obtained...
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Physicochemical and Mechanical Performance of Freestanding Boron-Doped Diamond Nanosheets Coated with C:H:N:O Plasma Polymer
PublicationThe physicochemical and mechanical properties of thin and freestanding heavy boron-doped diamond (BDD) nanosheets coated with a thin C:H:N:O plasma polymer were studied. First, diamond nanosheets were grown and doped with boron on a Ta substrate using the microwave plasma-enhanced chemical vapor deposition technique (MPECVD). Next, the BDD/Ta samples were covered with nylon 6.6 to improve their stability in harsh environments and...
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Structural and electrical transport properties of Pr-doped SrTi0.93Co0.07O3-δ a novel SOEC fuel electrode materials
PublicationSolid Oxide Electrolyzer Cells (SOECs) are very promising electrochemical devices for the production of syngas (H2/CO) by H2O and CO2 co-electrolysis. The structure, microstructure and electrical properties of the fuel electrode material play a crucial role in the performance of the whole cell and efficiency of electrocatalytic reduction of steam into hydrogen. In the present work, a novel Co and Pr co-doped SrTiO3-δ material attracted...
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Influence of controlled crystallization and SrF2 content on the structure and properties of Eu3+ doped phosphate glasses
PublicationNew phosphate glasses and glass-ceramics P2O5–Bi2O3–K2O–Nb2O5-SrF2 doped with Eu were synthesized and studied in this work. The influence of the SrF2 content (0–15 mol%) and the parameters of the heat treatment on their structural and optical properties were investigated. For the above purpose, the structural characterization by FTIR spectroscopy and XRD measurements was carried out, which showed a significant effect of SrF2 on...
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Wpływ modyfikacji strontem na strukturę i własności mechaniczne stopu AlSi10Mg=Strontium modyfication influence on the microstructure and properties of AlSi10Mg alloy
PublicationPrzedstawiono wyniki badań materiałowych stopu odlewniczego AlSi10Mg przed i po modyfikacji strontem. Wykazano korzystne zmiany w strukturze i wzrost własności mechanicznych na skutek modyfikacji stopu.
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Properties of Nanohydroxyapatite Coatings Doped with Nanocopper, Obtained by Electrophoretic Deposition on Ti13Zr13Nb Alloy
PublicationNowadays, hydroxyapatite coatings are the most common surface modification of long-term implants. These coatings are characterized by high thickness and poor adhesion to the metallic substrate. The present research is aimed at characterizing the properties of nanohydroxyapatite (nanoHAp) with the addition of copper nanoparticle (nanoCu) coatings deposited on the Ti13Zr13Nb alloy by an electrophoresis process. The deposition of...
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Unraveling the role of boron dimers in the electrical anisotropy and superconductivity in boron-doped diamond
PublicationWe use quantum mechanics (QM) to determine the states formed by B dopants in diamond. We find that isolated B sites prefer to form BB dimers and that the dimers pair up to form tetramers (BBCBB) that prefer to aggregate parallel to the (111) surface in the <110> direction, one double layer below the H-terminated surface double layer. These tetramers lead to metallic character (Mott metal Insulator Transition) with holes in the...
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Diamond-Phase (Sp3-C) Rich Boron-Doped Carbon Nanowalls (Sp2-C): A Physico-Chemical And Electrochemical Properties
PublicationThe growth of B-CNW with different boron doping levels controlled by the [B]/[C] ratio in plasma, and the influence of boron on the obtained material’s structure, surface morphology, electrical properties and electrochemical parameters, such as -ΔE and k°, were investigated. The fabricated boron-doped carbon nanowalls exhibit activity towards ferricyanide redox couple, reaching the peak separation value of only 85 mV. The flatband...
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Electro-chemo-mechanical properties in nanostructured Ca-doped ceria (CDC) by field assisted sintering
PublicationRecent investigations have shown that highly oxygen defective cerium oxides generate non-classical electrostriction that is superior to lead-based ferroelectrics. In this work, we report the effect of field-assisted spark plasma sintering (SPS) on electro-chemo-mechanical properties of calcium doped ceria (CDC). Nanometric powders of Ca.10 nm are rapidly consolidated to form polycrystalline nanostructures with a high degree of...
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Poly-L-Lysine-modified boron-doped diamond electrodes for the amperometric detection of nucleic acid bases
PublicationBoron-doped diamond (BDD) is a very promising supporting material used in the construction of biosensors for molecular recognition. The direct immobilization of structurally-organized huge molecules, such as poly-L-Lysine (PLL) provides the possibility of determining organic molecules, e.g. nucleic acid bases (e.g. adenine, guanine) or peptides and proteins. This paper describes the direct method for chemical and electrochemical...
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Formation of Highly Conductive Boron-Doped Diamond on TiO2 Nanotubes Composite for Supercapacitor or Energy Storage Devices
PublicationIn the present paper, we report the phenomena of the formation of the novel composite nanostructures based on TiO2 nanotubes (NTs) over-grown by thin boron-doped diamond (BDD) film produced in Microwave Plasma Enhanced Chemical Vapor Deposition (PE MWCVD). The TiO2 nanotube array overgrown by boron-doped diamond immersed in 0.1 M NaNO3 can deliver high specific capacitance of 7.46 mF cm−2. The composite electrodes were characterized...
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In-situ monitoring of electropolymerization processes at boron-doped diamond electrodes by Mach-Zehnder interferometer
PublicationIn this work, the Mach-Zehnder interferometer was designed to monitor the electrochemical processes conducted at boron-doped diamond electrode surface. The diamond electrodes were synthesized via Microwave Plasma-Assisted Chemical Vapor Deposition on optical grade quartz glass. The achieved transmittance in working are of diamond electrodes reached 55 %. A cage system-based Mach-Zehnder interferometer was used which allowed the...
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The electrochemical determination of isatin at nanocrystalline boron-doped diamond electrodes: stress monitoring of animals
PublicationUltra-thin nanocrystalline boron-doped diamond electrodes (B:NCD) were used for the electrochemical determination of isatin in dog urine samples using cyclic voltammetry and square wave voltammetry in a phosphate buffer saline, pH = 7.2. No additional modification or pretreatment of the electrode surface was required in this approach, being of high importance for the facile detection procedure. The increase of the peak current...
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The effect of boron concentration on the electrical, morphological and optical properties of boron-doped nanocrystalline diamond sheets: Tuning the diamond-on-graphene vertical junction
PublicationIn this paper, the effect of boron doping on the electrical, morphological and structural properties of free-standing nanocrystalline diamond sheets (thickness ~ 1 μm) was investigated. For this purpose, we used diamond films delaminated from a mirror-polished tantalum substrate following a microwave plasma-assisted chemical vapor deposition process, each grown with a different [B]/[C] ratio (up to 20,000 ppm) in the gas phase....
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Facile synthesis and characterization of graphene and N-doped graphene by CVD method from liquid precursors for promising electrode materials
PublicationIn this study, high-quality and few-layered graphene was synthesized using the chemical vapor deposition (CVD) method from liquid sources. Two different liquid carbon sources, pyridine, and benzene, were used and deposited on nickel foam under heat conditions using a bubbler in a quartz tube. X-ray diffraction (XRD) and Raman analysis confirmed the crystalline properties of graphene and N-doped graphene, demonstrating the high...
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Characterization of Optical and Electrical Properties of Transparent Conductive Boron-Doped Diamond thin Films Grown on Fused Silica
PublicationA conductive boron-doped diamond (BDD) grown on a fused silica/quartz has been investigated. Diamond thin films were deposited by the microwave plasma enhanced chemical vapor deposition (MW PECVD). The main parameters of the BDD synthesis, i.e. the methane admixture and the substrate temperature were investigated in detail. Preliminary studies of optical properties were performed to qualify an optimal CVD synthesis and film parameters...
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Optical and electrical properties of ultrathin transparent nanocrystalline boron-doped diamond electrodes
PublicationThe optical properties of ultrathin (less than 100 nm) boron-doped nanocrystalline diamond (B-NCD) film were investigated in a wavelength range of 200 ÷ 20000 nm. The B-NCD refractive index showed values close to that of monocrystalline diamond (n = 2.45) in a broad wavelength range (450 ÷ 4000 nm). A transmittance up to 70% and the average film thickness of 70 nm were achieved. A special cone-shaped shim was used in the deposition...
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Boron doped Nanocrystalline Diamond-Carbon Nanospike Hybrid Electron Emission Source
PublicationElectron emission signifies an important mechanism facilitating the enlargement of devices that have modernized large parts of science and technology. Today, the search for innovative electron emission devices for imaging, sensing, electronics, and high-energy physics continues. Integrating two materials with dissimilar electronic properties into a hybrid material is an extremely sought-after synergistic approach envisioning a...
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Correlations of structural, thermal and electrical properties of sodium doped complex borophosphosilicate glass
PublicationBorophosphosilicate glasses with varying sodium ion concentrations were investigated for their, structural, thermal, and electrical properties. All the obtained glasses were transparent except the glass with the highest sodium content, which exhibited translucency due to inhomogeneities. Increasing sodium content led to reduced boron and silicon content while maintaining a constant B/Si ratio, indicating progressive depolymerization...