Glycine Nitrate Process Research Articles

Magnetocaloric effect of polycrystalline La0.5Sm0.2Sr0.3Mn1-xCrxO3 (0 ≤ x ≤ 0.20) compound prepared by glycine-nitrate process

Magnetocaloric effect of polycrystalline La0.5Sm0.2Sr0.3Mn1-xCrxO3 (0 ≤ x ≤ 0.20) compound prepared by glycine-nitrate process

Effect of Synthesis Method of Nickel–Samarium-Doped Ceria Anode on Distribution of Triple-Phase Boundary and Electrochemical Performance

Two-dimensional (2D) electron back scattered diffraction (EBSD) is a powerful tool for microstructural characterization of crystalline materials. EBSD enables visualization and quantification of the effect of synthesis methods on the microstructure of individual grains, thus correlating the microstructure to mechanical and electrical efficiency. Therefore, this work was designed to investigate the microstructural changes that take place in the Ni-SDC cermet anode under different synthesis methods, such as the glycine–nitrate process (GNP) and ball-milling. EBSD results revealed that different grain size and distribution of Ni and SDC phases considerably influenced the performance of the Ni–SDC cermet anodes. The performance of the Ni–SDC cermet anode from GNP was considerably higher than that of Ni-SDC from ball-milling, which is attributed to the triple-phase boundary (TPB) density and phase connectivity. Due to the poor connectivity between the Ni and SDC phases and the development of large Ni and SDC clusters, the Ni-SDC cermet anode formed by ball milling had a lower mechanical and electrical conductivity. Moreover, the Ni–SDC cermet anode sample obtained via GNP possessed sufficient porosity and did not require a pore former. The length and distribution of the active TPB associated with phase connectivity are crucial factors in optimizing the performance of Ni-SDC cermet anode materials. The single cell based on the Ni–SDC composite anode prepared through GNP exhibited a maximum power density of 227 mW/cm2 and 121 mW/cm2 at 800 °C in H2 and CH4, respectively.

Univariate and multivariate analyses of Gd in gadolinia-doped ceria using laser-induced breakdown spectroscopy

We report laser-induced breakdown spectroscopy (LIBS) analysis of gadolinium (Gd) in gadolinium-doped ceria (GDC), the functional material used in solid oxide fuel cells (SOFCs). LIBS using laser ablation to atomize solid samples is competent in sampling the refractory ceria. Also, a few to 10 mol.% of Gd is doped in GDC to be used for SOFCs. Such a high concentration requires additional dilution after acid digestion of the sample for conventional analyses. LIBS with typical dynamic range from ppm to percent can analyze the high concentrations of Gd directly. GDCs with 1–10 mol.% of Gd were synthesized by glycine-nitrate process and the LIBS spectra were recorded. In spite of these advantages of LIBS, calibrating LIBS spectra to the concentrations of Gd is quite challenging due to rich emissions of Ce. Six prominent Gd I lines were selected for univariate calibrations and the whole spectra were used for multivariate partial least squares-regression (PLS-R) modeling. The PLS-R model considering emission intensities of both matrix and analyte elements outperformed the univariate calibrations. Our results suggest that LIBS in combination with multivariate analysis can be useful as an analysis method for the refractory lanthanide oxide materials.

Efficient Electrocatalyst for Hydrogen Evolution Reaction based on N-rGO-MWCNT/CuAlO2 Nanocomposite in Acidic Media

The CuAlO2 delafossite complex was incorporated with nitrogen-doped reduced graphene oxide (N-rGO) and multiwalled carbon nanotubes (MWCNT) based nanocomposite (N-rGO-MWCNT/CuAlO2) for the hydrogen evolution reaction (HER). The CuAlO2 delafossite complex was made by self-combustion glycine nitrate process (GNP), and the N-rGO-MWCNT composite was prepared by the hydrothermal method. The morphology was characterized by spectroscopy and microscopy techniques. The materials were structurally well ordered with a porous structure and high surface area. The GCE/N-rGO-MWCNT/CuAlO2 electrode exhibited electrocatalytic activity for the hydrogen evolution reaction (HER) under strongly acidic conditions with a low over-potential, increasing reduction current, and a small Tafel slope of 48 mV dec−1 at 10 mA cm−1 with long-term stability under operating conditions.

Physico-electrochemical properties and long-term stability of Mn1.45-0.5xCo1.45-0.5xCuxY0.1O4 spinel protective coatings on commercial metallic interconnects for solid oxide fuel cells

The application of ceramic coatings has been presented as an effective method to suppress the oxidation scale growth and Cr evaporation of ferritic stainless steels used in solid oxide fuel cell (SOFC) interconnects. In this work, Mn1.45-0.5xCo1.45-0.5xCuxY0.1O4 materials with various Cu contents (x=0.1, 0.3, and 0.5) were synthesized through a facile glycine nitrate process as a protective coating on a metallic interconnect (SUS 441). It was observed that the lattice parameter decreased from 8.31Å (x=0.1) to 8.22Å (x=0.5) with increasing Cu content (x). The effects of Cu content (x) on the phase stability as well as sintering, electrical, and thermal expansion were investigated. The results confirmed that the Mn1.3Co1.3Cu0.3Y0.1O4 spinel had the highest electrical conductivity of 115 Scm−1 at 800°C and an average thermal expansion value of 11.98×10−6K−1 in the temperature range of 20–1000°C. The ASR of Mn1.3Co1.3Cu0.3Y0.1O4 coated SUS441 (7.7×10−5Ω-cm2 at 800°C) was 3 orders of magnitude lower than that of the uncoated sample. Moreover, the Mn1.3Co1.3Cu0.3Y0.1O4 coated interconnect exhibited excellent long-term stability up to 1000h at 800°C without any observable degradation, while the ASR of the uncoated sample increased by >850% for 1000h (from 0.001Ω-cm2 to 0.06Ω-cm2) under the same conditions. The oxidation kinetics obeying the parabolic law with a rate constant of Mn1.3Co1.3Cu0.3Y0.1O4 (1.64×10−9mg2cm−4s−1) was 4 orders of magnitude lower than that of bare SUS 411 (7.4×10−5mg2cm−4s−1) at 750°C for 2000h. These results demonstrate that the Mn1.3Co1.3Cu0.3Y0.1O4 is a promising coating material with high electrical conductivity and excellent durability for metallic interconnects of intermediate-temperature SOFCs.

Pt/CeO2 catalyst synthesized by combustion method for dehydrogenation of perhydro-dibenzyltoluene as liquid organic hydrogen carrier: Effect of pore size and metal dispersion

Liquid organic hydrogen carrier (LOHC) is a chemical hydrogen storage method that stores hydrogen in the form of liquid organics. Dibenzyltoluene (DBT) is a promising LOHC material due to its high storage density, low ignitability, and low cost. In this study, Pt/Al2O3 and Pt/CeO2 catalysts are synthesized using a combustion nanocatalyst synthesis method called the glycine nitrate process (GNP) to obtain high catalytic activity for the dehydrogenation of perhydro-dibenzyltoluene (H18-DBT). Pt/CeO2 exhibits much faster dehydrogenation than Pt/Al2O3, 80.5%/2.5 h versus 3.5%/2.5 h. To investigate the causes of the difference in the dehydrogenation rates, microstructural characterization by N2 physisorption, CO chemisorption and transmission electron microscopy analysis are conducted, and the catalytic activities are evaluated at various liquid hourly space velocities (LHSVs). The differences in dehydrogenation can be attributed to the mass transport of liquid H18-DBT into the catalyst pores being slow due to the small pores in Pt/Al2O3, which is a rarely addressed issue for other LOHC materials. This is because many LOHC materials are dehydrogenated at the gas phase, which has higher diffusivity than that of the liquid phase. Pt/CeO2 synthesized by the GNP is also compared with a commercial Pt/Al2O3 catalyst. The commercial Pt/Al2O3 catalyst shows a dehydrogenation of 17.8%/2.5 h, which is much slower than that of Pt/CeO2 synthesized by the GNP, at 80.5%/2.5 h.

Highly sensitive and selective electrochemical detection of dopamine based on CuCrO2-TiO2 composite decorated screen-printed modified electrode

In the present study, a dopamine (DA) sensor was constructed based on a screen-printed carbon electrode (SPCE) combined with CuCrO2-TiO2 composite. The CuCrO2-TiO2 composite was prepared by a self-combustion glycine nitrate process (GNP) and used to the selective and sensitive detection of DA. The prepared CuCrO2-TiO2 composite-modified SPCE electrode revealed an enhanced sensor response to the detection of DA, showing high peak current with less oxidation potential. The surface area and phase evolution of the CuCrO2-TiO2 composite were determined by the glycine-nitrate (GN) ratios. The structures of the prepared material were verified by scanning electron microscopy, X-ray diffraction, and scanning transmission electron microscopy studies. The active surface area of the composite was identified by BET surface area analysis. These studies confirmed the porous structure of the CuCrO2-TiO2 composite. The electrochemical performance of the SPCE/CuCrO2-TiO2 electrode was studied by cyclic voltammetry, electrochemical impedance spectroscopy, and differential pulse voltammetry methods. The SPCE/CuCrO2-TiO2 (GN = 1.5) electrode presented distinguished electrocatalytic activity for the detection of DA with a long linear response range (1–230 µM), low detection limit (0.14 µM), and high sensitivity (16.82 µA µM−1 cm−2). The modified sensor also showed outstanding repeatability, storage stability, reproducibility, and along with acceptable practicality.

Tri-Functional Double Perovskite Oxide Catalysts for Fuel Cells and Electrolyzers.

Perovskite oxides are at the forefront of the race to develop catalysts/electrodes for fuel cells and electrolyzers. This work presents trifunctional properties of the double-perovskite oxide PrBa0.5 Sr0.5 Co1.5 Fe0.5 O5+δ and the PrBa0.5 Sr0.5 Co1.5 Fe0.5 O5+δ -Ag composite prepared by the glycine nitrate process. The electrocatalytic studies reveal that the Ag-based composite is an excellent catalyst for both oxygen evolution (OER) and hydrogen evolution reactions (HER) in alkaline solution. The electrochemical impedance spectroscopy analysis through distribution function of relaxation times (DFRT) suggests that the improved activity originates from the suppression of resistance contributed by various relaxation processes. The oxygen reduction reaction (ORR) kinetics in these oxide-based cathodes has been studied by performing symmetric-cell measurements at high temperatures using both oxygen-ion and proton-conducting cells. DC bias dependence of charge-transfer processes, oxygen-surface kinetics, polarization resistances, and activation energies are revealed by DFRT studies. Ag addition in PrBa0.5 Sr0.5 Co1.5 Fe0.5 O5+δ leads to enhanced kinetics of OER, HER, and ORR.

Glycine–Nitrate Combustion Synthesis of Cu-Based Nanoparticles for NP9EO Degradation Applications

Copper-based nanoparticles were synthesized using the glycine–nitrate process (GNP) by using copper nitrate trihydrate [Cu(NO3)2·3H2O] as the main starting material, and glycine [C2H5NO2] as the complexing and incendiary agent. The as-prepared powders were characterized through X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET), X-ray photoelectron spectroscopy (XPS), and scanning electron microscopy analysis. Using Cu(NO3)2·3H2O as the oxidizer (N) and glycine as fuel (G), we obtained CuO, mixed-valence copper oxides (CuO + Cu2O, G/N = 0.3–0.5), and metallic Cu (G/N = 0.7). The XRD and BET results indicated that increasing the glycine concentration (G/N = 0.7) and reducing the particle surface area increased the yield of metallic Cu. The effects of varying reaction parameters, such as catalyst activity, catalyst dosage, and H2O2 concentration on nonylphenol-9-polyethoxylate (NP9EO) degradation, were assessed. With a copper-based catalyst in a heterogeneous system, the NP9EO and total organic carbon removal efficiencies were 83.1% and 70.6%, respectively, under optimum operating conditions (pH, 6.0; catalyst dosage, 0.3 g/L; H2O2 concentration, 0.05 mM). The results suggest that the removal efficiency increased with an increase in H2O2 concentration but decreased when the H2O2 concentration exceeded 0.05 mM. Furthermore, the trend of photocatalytic activity was as follows: G/N = 0.5 > G/N = 0.7 > G/N = 0.3. The G/N = 0.5 catalysts showed the highest photocatalytic activity and resulted in 94.6% NP9EO degradation in 600 min.

A novel IR-transparent Ho3+:Y2O3–MgO nanocomposite ceramics for potential laser applications

The work is devoted to obtaining of transparent nanocomposite materials as low loss, highly thermally conductive materials for potential laser applications. We report Ho3+:Y2O3–MgO nanocomposite ceramics with excellent mechanical and optical properties by combining glycine-nitrate process and spark plasma sintering. Morphology, structural-phase state, infrared transmittance and luminescence depending on the holmium concentration (0–12 at.%) were studied for the first time. It was found that optical transmittance reaches 75%@6000 nm for 3 at.% Ho3+:Y2O3–MgO ceramics. The absorption cross-section at 1931 nm and the emission cross-section at 2118 nm were determined to be σabs = 0.51 × 10−20 cm2 and σem = 0.29 × 10−20 cm2, respectively. Based on the testing results of luminescent characteristics it was demonstrated that Ho3+:Y2O3–MgO nanocomposite is a promising material for high-power eye-safe lasers operating in the 2 μm wavelength range.

Synthesis of Nanostructured Li4Ti5O12 Powder by the Glycine–Nitrate Process and a Modified Glycine–Nitrate Process

We have studied the influence of the glycine : nitrate (G/N) ratio and heat treatment temperature on characteristics of nanocrystalline Li4Ti5O12 powders synthesized from titanium tetrabutylate and lithium carbonate via combustion of an aqueous–organic precursor, followed by heat treatment. At the optimum reactant ratio G/N = 0.7, the content of the Li4Ti5O12 phase after heat treatment of the powders for 2 h at 700°C is 97% and the crystallite size is 100 nm. It has been shown that modifying the glycine–nitrate process by adding citric acid to solution (CitH3/ΣM = 0.37–0.56) allows one to improve the homogeneity of the components in the precursor, thus ensuring the preparation of single-phase powders.

Self-assembled cubic-hexagonal perovskite nanocomposite as intermediate-temperature solid oxide fuel cell cathode

Self-assembly is an emerging strategy for preparing composite cathodes with good oxygen electrochemical reduction activity and congenital chemical compatibility for intermediate-temperature solid oxide fuel cell (IT-SOFC). Here we report that a self-assembled BaCo0.6Zr0.4O3-δ (BZC-BC) nanocomposite is prepared through one-pot glycine-nitrate process and exhibits high cathode performance. The BZC-BC nanocomposite is composed of 62 mol% cubic perovskite BaZr0.82Co0.18O3-δ (BZC) as an ionic conductor and 38 mol% hexagonal perovskite BaCo0.96Zr0.04O2.6+δ (12H-BC) as a mixed ionic and electronic conductor. The BZC-BC nanocomposite has the pomegranate-like particles aggregated with a larger number of nanoparticles (50-100 nm) which greatly enlarge the three-phase boundary sites. The BZC-BC nanocomposite exhibits a thermal expansion coefficient of 12.89 × 10−6 K−1 well-matched with that of Ce0.8Gd0.2O3-δ (12.84 × 10−6 K−1) electrolyte. The high electro-catalytic activity of BZC-BC nanocomposite cathode for oxygen reduction is reflected by the low polarization resistances of oxygen ions incorporation at cathode/electrolyte interface (0.02823 Ω cm2), oxygen species diffusion (0.03702 Ω cm2) and oxygen adsorptive dissociation (0.07609 Ω cm2) at 700 °C. The single cell with BZC-BC nanocomposite cathode achieves the maximum power density of 1094 mW cm−2 at 650 °C and shows good stability under 25 h run.

Effect of processing route on the properties of LSCF-based composite cathode for IT-SOFC

A novel processing technique was developed to produce an in-situ nano-composite powder based on $$\hbox {La}_{0.6}\hbox {Sr}_{0.4}\hbox {Co}_{0.2} \hbox {Fe}_{0.8}\hbox {O}_{3\text {-}{\updelta }}$$ (LSCF6428) and $$\hbox {Gd}_{0.1}\hbox {Ce}_{0.9}\hbox {O}_{1.95}$$ (GDC10) for application as cathode material in intermediate temperature solid oxide fuel cells (IT-SOFC). The nano-composite powder was produced using glycine-nitrate solution combustion technique starting from nitrates of six metal ions. The synthesized powder was characterized using X-ray diffraction (XRD), transmission electron microscopy (TEM), particle size and BET surface area analyses. XRD analysis of as-produced nano-composite powder confirmed the formation of desired phases right after combustion synthesis. The structural parameters of different phases present in the powders were estimated through Rietveld refinement of XRD data. To compare the electrical properties of nano-composite cathode powder produced through the present method, nano-powders of GDC10 and LSCF6428 were individually produced through glycine nitrate process and subsequently mixed through solid-state technique and characterized for functional properties. Using this in-situ nano-composite material, lower polarization resistance was achieved as compared to the LSCF–GDC composite produced from mechanical mixtures of nano-powders of GDC10 and LSCF6428 when used as cathode in GDC10 electrolyte-based symmetrical cell. The effects of cathode layer thickness and electrode firing temperature on the cathodic polarization resistance were studied using in-situ nano-composite cathode powder.

CuFeO2–CeO2 nanopowder catalyst prepared by self-combustion glycine nitrate process and applied for hydrogen production from methanol steam reforming

Hydrogen (H2) is being considered as an alternate renewable energy carrier due to the energy crisis, climate change and global warming. In the chemical industry, hydrogen production is mainly accomplished by the steam reforming of natural gas. In the present study, CuFeO2–CeO2 nanopowder catalyst with a heterogeneous delafossite structure was prepared by the self-combustion glycine nitrate process and used for steam reforming of methanol (SRM). The precursor solution was fabricated from Cu–Fe–Ce metal-nitrate mixed with glycine and an aqueous solution. The prepared CuFeO2–CeO2 nanopowder catalyst was studied by different physical and chemical characterization techniques. The prepared CuFeO2–CeO2 nanopowder catalyst was immensely porous with a coral-like structure. The BET surface area measurement revealed that the specific surface area of as-combusted CuFeO2–CeO2 nanopowder varied from 5.6248 m2/g to 19.5441 m2/g. In addition, the production rate of CuFeO2–CeO2 was improved by adding CeO2 and adjusting the feeding rate of the methanol. The highest H2 generation rate of the CuFeO2–CeO2 catalyst was 2582.25 (mL STP min−1 g-cat−1) at a flow rate of 30 sccm at 400 °C. Hence, the high specific surface area of the 70CuFeO2–30CeO2 nanopowder catalyst and the steam reforming process could have a very important industrial and economic impact.

Synthesis of molybdates Zn1-xCoxMoO4 (0 ≤ x ≤ 1), by decomposition of the precursors developed by the glycine-nitrate process (GNP), and their characterization

Nanocrystals of zinc-cobalt molybdate (Zn1-xCoxMoO4) were prepared by the glycine-nitrate process (GNP) route with a glycine/nitrate ratio of 2:3 and compared to the solid state synthesis. The obtained powders were characterized by thermal analysis (TGA-TDA), X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and Raman spectroscopy. The morphology was examined by scanning electron microscopy (SEM) and Brunauer–Emmett–Teller (BET). The particle size was determined by transmission electron microscopies (TEM). UV–Visible spectroscopy and CIE L*a*b* colorimetric parameters have been used for the colour characterisation and measurement. The compounds obtained present two single-phased domains regardless of the synthesis method. The first domain of blue colour corresponding to a level of cobalt x such as: 0 = x ≤ 0.3, isostructural with α-ZnMoO4 of triclinic symmetry and the second domain of green colour, for cobalt x levels such as: 0.45 = x ≤ 1 isostructural with α-CoMoO4 of monoclinic structure. The Zn0.7Co0.3MoO4 powders obtained at 700 °C by GNP route and synthesized in acidic environment were formed of particles of quasi-spherical morphology, with average size of crystallites estimated between 80 - 140 nm.

Structural, Microstructural and Electrochemical Studies of Co/Mn Derived Oxides as Protective Layers for Intermediate Temperature SOFCs

Abstract. Designing highly protective and superior electrically conductive coatings from Cobalt-manganese doped/un-doped oxide materials (CMOs) is the main target of this study. The as-prepared nanopowders were synthesized via glycine nitrate process (GNP) at moderate annealing temperature afterword characterized using several techniques including X-rays diffraction (XRD), Field emission scanning electron microscopy (FE-SEM) and electrochemical impedance measurements at room temperature. The XRD results revealed a pure phase of spinel structure with particle size range 75-81 nm for the doped CMO samples. SEM micrographs exhibited morphology with fine aggregate of particles. The incorporation of different ions of Cu, Ni, Fe and Na into the CMOs structure showed a significant increase in the diffusivity of ions and remarkable improvement in the crystallinity. AC electrical conductivity was also measured for the compacted pellets after sintering at 850°C using the electrochemical impedance spectroscopy technique at room temperature. From the obtained results it could be concluded that the polarization resistance of pure and modified CMOs samples show similar behavior ranged from 5 to 6 k Ω.

Performance of Ni/10Sc1CeSZ anode synthesized by glycine nitrate process assisted by microwave heating in a solid oxide fuel cell fueled with hydrogen or methane

Nickel/scandia-ceria-stabilized-zirconia (Ni/10Sc1CeSZ) cermet is a potential anode for solid oxide fuel cells. The anode powder is prepared through a microwave-assisted glycine nitrate combustion process, and its properties, including phase and chemical composition as well as morphology, are characterized by XRD, TEM, and EDS techniques. The electrical conductivity and electrochemical behavior under low concentration of dry hydrogen (H2:N2 volume ratio = 10:90) and dry methane (CH4:N2 volume ratio = 50:50) fuels are determined. XRD results show two phases, namely, cubic NiO phase and cubic 10Sc1CeSZ phase, with the crystallite sizes of 67 and 40 nm, respectively. The area specific resistances (ASRs) of the prepared anode measured using a symmetrical cell of Ni/10Sc1CeSZ|10Sc1CeSZ|Ni/10Sc1CeSZ are 0.96 and 24.3 Ω cm2 observed at 800 °C in dry low hydrogen concentration (10 vol% hydrogen–90 vol% nitrogen) and dry methane (50 vol% methane–50 vol% nitrogen) fuels, respectively. The ASR in methane fuel is higher than that in hydrogen fuel at all operating temperatures (600–800 °C) because of carbon deposition. The amount of deposited carbon and degree of graphitization (IG/ID) of this anode after exposure in methane at 800 °C for 3 h are 4.34% and 2.1, respectively. Overall, Ni/10Sc1CeSZ cermet synthesized by glycine nitrate process assisted with microwave-heating technique exhibits acceptable electrochemical behavior even at low hydrogen concentration and also in dry methane. This can be related to the improved powder morphology as a result of uniform heating assisted by microwave energy.

Photocatalytic Activity of Cu-based Nanoparticles Synthesized by Glycine-Nitrate Combustion Technique

The copper based nanoparticles was synthesized by glycine-nitrate process (GNP), using copper nitrate trihydrate [Cu(NO3)2 · 3H2O] as main starting materials and glycine [C2H5NO2] as complexant and incendiary agent. The as-prepared powders were characterized by X-ray diffraction (XRD), and scanning electron microscopy (SEM) techniques. Results of the photocatalytic degradation of Nonylphenol polyethoxylates (NP9EO) in a custom-made photoreactor indicated that the maximum degradation (more than 94% and 70% TOD removal) of NP9EO occurred with CuO+Cu2O composite catalyst (dosage of 0.3 g/L) when a combination of ultraviolet (UV) irradiation for 600 min, and a heterogeneous system was used.

Rational synthesis of 10GDC electrolyte through a microwave irradiation GNP facile route for SOFC applications.

The gadolinium-doped ceria Gd0.1Ce0.9O1.95 (10GDC) powder was synthesized using a microwave-synthesized glycine nitrate process (MS-GNP). The powder was subsequently pressed into circular pellets and sintered at various temperatures viz. 800, 900, 1000 and 1200 °C, in a microwave, high temperature furnace for 4 h so as to investigate the effect of the sintering temperature and sintering environment on the structural, morphological, thermal and electrical properties. The crystallite size and particle size as observed from X-Ray Diffraction (XRD) and Field Emission Scanning Electron Microscopy (FESEM) are found to be in the range of 15–28 nm and 12–20 nm, respectively. The electrochemical impedance spectroscopy (EIS) analysis was carried out to study the electrochemical properties during the cooling cycle from 400 °C to 800 °C. The highest value of ionic conductivity (3.55 × 10−1 S cm−1) is observed at an operating temperature of 800 °C and O2 gas partial pressure of 1 atm. Further, it is observed that the sintering temperature has a significant effect on the surface morphology and crystallite size, thereby improving the electrical performance of the samples. Though 20GDC was used as an electrolyte in the authors' previous study, the novelty of the present work is the synthesis of 10GDC using a microwave-assisted glycine nitrate process and the size (thickness) of the prepared electrolyte for use in a Solid Oxide Fuel Cell (SOFC), which plays a major role in enhancing the structural, morphological and electrochemical properties with respect to different sintering temperatures as compared to the reported data. Hence, the prepared 10GDC electrolyte may be treated as one of the promising candidates as an electrolyte for SOFC for intermediate as well as high temperature applications.

Influence of sintering temperature on structural and optical properties of Y2O3–MgO composite SPS ceramics

The paper studies infrared-transparent 50:50 vol% Y2O3–MgO fine-grained composite ceramics produced via glycine-nitrate process and spark plasma sintering (SPS). Effect of SPS temperature (T = 1100, 1200, 1250 and 1300 °С) on consolidation processes of Y2O3–MgO nanopowders and on ceramics properties has been investigated. Morphology, structural-phase state, density, Vickers microhardness and infrared transmittance of Y2O3–MgO nanocomposites have been studied. Transmittance has been found to increase with the SPS temperature reaching 71%@6000 nm wavelength at T = 1300 °C. Maximal Vickers hardness of 10.9 GPa has been achieved at T = 1200 °C. The correlation between processing conditions of ceramics and indicated characteristics was investigated.