Low-temperature Solid-state Reaction Research Articles

Synthesis and investigation of the optical characteristics of RE3+ activated Ca2Li2Si2O7 (Rare earth = Eu, Tb) phosphor for W-LED application

Novel Eu3+ and Tb3+ ions-doped Ca2Li2Si2O7 luminescent materials were prepared by a low-temperature solid-state reaction technique for LED application. The electronic transitions of 5D0 → 7F2 (Eu3+) and 5D4 → 7F5 (Tb3+) have caused the luminescent material to exhibit strong luminosity in 613 nm (red) and 545 nm (green), respectively. Fourier transform infrared (FT-IR) spectra were applied for the identification of functional groups, and powder X-ray diffraction (XRD) was used for structural analysis. Morphological data was gathered using scanning electron microscopy (SEM). Its color was also determined by calculating the CIE coordinates. The excitation, PL properties, and luminescence decay time of the emission transitions of Eu3+ (5D0 → 7F2) and Tb3+ (5D4 → 7F5) were measured in order to analyze luminosity spectra.

Unlocking the Potential of Garnet Ferrites: A Comprehensive Review on Properties, Preparation Methods, and Applications

Abstract This review paper provides a comprehensive overview of the recent advances in garnet ferrites, a class of complex magnetic oxides with promising properties for various applications. The paper covers the crystal structure and different properties of garnet ferrites as well as their synthesis methods, including sol-gel auto-combustion, low-temperature liquid phase epitaxy, pulsed laser deposition, coprecipitation method, sol-gel, hydrothermal, ball billing method, and low-temperature solid-state reactions. The functional properties of garnet ferrites, such as permeability, hysteresis loop, loss mechanics, and saturation magnetization, are also discussed in detail, along with their potential applications in microwave devices, antennas, Faraday lasers, and cancer treatment. Finally, the challenges and future directions for the development of garnet ferrites are outlined, highlighting the need for further research to optimize their properties and improve their performance in real-world applications.

The study of Correlated Barrier Hopping (CBH) conduction mechanism and modulus spectroscopy of YFe0.5Co0.5O3 compound

This research paper studied the electrical properties of Yttrium orthoferrite by substituting 50-mol percent of Co into the Fe-site. The crystalline morphology of the obtained compound, YFe0.5Co0.5O3, was studied using XRD and Rietveld refinement with FullProf software. A low-temperature solid-state reaction technique was used to make this compound. X-ray diffraction results indicate that the obtained compound has an orthorhombic structure with space group Pbnm. X-ray peak broadening analysis was used to evaluate crystallite size and strain using Williamson-Hall plots (W–H plot). FESEM with EDX data revealed the phase purity of the obtained compound. XPS studies showed the presence of multiple oxidation states of Fe and Co in the compound. The Nyquist plots show non-Debye-type behavior in all samples. The CBH (Correlated Barrier Hopping) Model was adopted to explain the conduction mechanism.

Antimicrobial activity of Cobalt doped Cerium Oxide (Co-CeO2) nanoparticles against selected food pathogens

This present work is to investigate the antibacterial activity of CeO2 nanoparticles on five foodborne pathogens. Low-temperature solid-state reactions were used to create co-doped CeO2 nanoparticles (Co-CeO2 NPs). In the current work, the impact of Co-doping on polycrystalline CeO2 samples synthesized using the co-precipitation method at room temperature for Co-doping concentrations of 0.5%, 1%, 3%, and 5% is discussed. Rietveld refinement of the X-ray diffraction patterns confirms that the Co-doped CeO2 samples have a face-centred cubic structure. This shows that the Co ions have been successfully integrated into the CeO2 lattice. Also, the UV-Vis-NIR absorption spectra confirm that redshifts do happen in the Co-doped CeO2 samples, which shows that the band gap energy decreases as the number of Co ions grows. In an antibacterial test against five pathogenic microbes, S. aureus, M. luteus, Enterobacter aerogenes, S. typhi, and Pseudomonas aeruginosa, Co-doped cerium oxide nanoparticles significantly slowed the growth of all five pathogens, both in liquid and solid growth conditions. These results show that Co-doped CeO2 nanoparticles have strong antibacterial properties against foodborne pathogens. This suggests that they could be used as promising bionanomaterials for in vivo therapeutic uses.

Effect of Sm3+ ions doping on the structural and optical properties, Judd-Ofelt and radiative parameters of ZnS phosphor materials

Undoped ZnS and Sm3+ doped with varying concentration of ZnS phosphor materials were synthesized via low temperature solid state reaction method. The samples were investigated for the influence of different concentrations of Sm3+ ions on their structural and spectroscopic properties. The presence of various absorption bands in UV–Vis–NIR spectra revealed the transition from ground state to different excited states of Sm3+ ions. The Judd-Ofelt (JO) analyses were evaluated to identify the structure and the bonding around the Sm3+ ions. The high value of Ω2 intensity parameter reveals that the site symmetry is lower. The parameters such as radiative transition probabilities, radiative lifetime, branching ratio, stimulated emission cross-sections and the optical gain parameters are also evaluated. The PL spectra shows five high intensity emission bands centered at 567 nm, 590 nm, 619 nm, 641 nm and 667 nm corresponding to 4G5/2→6Hj (j = 5/2, 7/2,9/2, 11/2, 13/2) transitions and showed optimum for concentration at x = 0.03 in Zn(1-x)S. The quantum yield of the prepared optimal phosphor using integrating sphere method was found to be 10.08%. This indicates that the materials synthesized may be favorable for the applications of laser and other optical devices.

Infrared Spectroscopic Studies of Oxygen Atom Quantum Diffusion in Solid Parahydrogen.

The thermally induced diffusion of atomic species in noble gas matrices was studied extensively in the 1990s to investigate low-temperature solid-state reactions and to synthesize reactive intermediates. In contrast, much less is known about the diffusion of atomic species in quantum solids such as solid parahydrogen (p-H2). While hydrogen atoms were shown to diffuse in normal-hydrogen solids at 4.2 K as early as 1989, the diffusion of other atomic species in solid p-H2 has not been reported in the literature. The in situ photogeneration of atomic oxygen, by ArF laser irradiation of an O2-doped p-H2 solid at 193 nm, is studied here to investigate the diffusion of O(3P) atoms in a quantum solid. The O(3P) atom mobility is detected by measuring the kinetics of the O(3P) + O2 → O3 reaction after photolysis via infrared spectroscopy of the O3 reaction product. This reaction is barrierless and is thus assumed to be diffusion-controlled under these conditions such that the reaction rate constant can be used to estimate the oxygen atom diffusion coefficient. The O3 growth curves are well fit by single exponential expressions allowing the pseudo-first-order rate constant for the O(3P) + O2 → O3 reaction to be extracted. The reaction rates are affected strongly by the p-H2 crystal morphology and display a non-Arrhenius-type temperature dependence consistent with quantum diffusion of the O(3P) atom. The experimental results are compared to H(2S) atom reaction studies in p-H2, analogous studies in noble gas matrices, and laboratory studies of atomic diffusion in astronomical ices and surfaces.

In situ TEM study of Ni-silicides formation up to 973K

Low-temperature solid-state reactions between Ni and Si were studied using in situ transmission electron microscopy (TEM). In the experiments thin amorphous silicon (a-Si) films were laid on Ni micro-grids and heated up to 973 K. In our approach the supporting Ni-grid serves as an unlimited source of nickel to successively form the whole range of Ni-silicide phases while diffusing into amorphous silicon. Unlike other thin film experiments where Ni and Si are layered on top of each other, our arrangement enables lateral diffusion of Ni along the Si layer and therefore enables the formation and study of successive Ni-Si phases side by side. That allowed us to observe in situ α-NiSi2 as the first reaction product, in contrast to most studies that had reported either δ-Ni2Si or θ-Ni2Si as the first phase to form. α-NiSi2 was continuously present at the reaction front propagating into the a-Si film. The phase sequence followed the increasing Ni concentration from a-Si towards the Ni-grid: α-NiSi2, NiSi, Ni3Si2, δ-Ni2Si, γ-Ni31Si12 and Ni3Si. Almost all known Ni-silicide phases were found to form at relatively low temperatures except the θ-Ni2Si, β-NiSi2 and β3-Ni3Si. The dominant phase was γ-Ni31Si12 which appeared in three structural modifications, differing in lattice periodicity along the c-axis. The periodicity of the basic γ-Ni31Si12 structure along the c-axis is ~12 Å (c0 = 12.288 Å) and that of the other two modifications were ~18 Å and ~36 Å, denoted by S12, S18 and S36 respectively. Of the three, only S12 has a structural model, S18 had been previously observed by Chen, but S36 had not been documented in previous works. During our in situ heating experiments, in addition to the Ni-silicide layer formation a new phenomenon was observed, namely the appearance, growth and transformation of Ni-silicide whiskers which was attributed to the accumulation of compressive stress in the thin layer.

Influence of LTSSR and HTSSR synthesis methods on the structural properties of YFeO3 orthoferrite

The YFO ceramics have been synthesized using High Temperature Solid State Reaction (HTSSR) as well as Low Temperature Solid State Reaction (LTSSR) technique in powder form. The Perovskite orthorhombic YFeO3 phase has been identified in the x-ray studies of the powder samples prepared with HTSSR technique. In addition, 24 % of Y2O3 phase is also detected in the HTSSR powder samples. This phase reduced with increasing calcination time, however could not be suppressed below 8 % even after calcination for 72 h. Whereas, the powder samples prepared using LTSSR technique exhibit only pure YFeO3 phase, on calcination at 950 °C for 6hrs.Therefore found a more convenient and less time-consuming technique for the development of the orthorhombic YFeO3phase in YFO ceramics.

Novel green-emitting copper-doped Cs<sub>2</sub>ZnCl<sub>4</sub> synthesized via low-temperature solid-state reaction using a small amount of water

Novel green-emitting copper-doped Cs<sub>2</sub>ZnCl<sub>4</sub> synthesized via low-temperature solid-state reaction using a small amount of water

Fluorine-free synthesis and characterization of vanadium-zircon (V–ZrSiO4) turquoise ceramic pigment by a low temperature solid state reaction route

A fluorine-free and low temperature synthetic route derived from in-situ formed mineralizer has been developed to fabricate V–ZrSiO4 turquoise ceramic pigment. When the calcination temperature is 750 °C and mole ratio of Na3VO4 to ZrOCl2·8H2O (NV/Zr) is 0.3, the as-prepared pigment exhibits a cluster-like structure and deep blue hue (L* = 69.28, a* = −12.15, b* = −20.04). The solid state reaction taking place during the mechanical grinding process lead to the in-situ formation of mineralizer NaCl and certain Si–O–Zr bond. The XRD refinement results and hyperfine structure in EPR spectra indicate that vanadium is located at the zircon interstitial site 16g with an isolated V4+ cluster state. The enameled samples exhibit excellent coloring ability, high chemical and thermal stability, suggesting its potential application in ceramic decoration.

Synthesis and characterization of Fe3-xSnxO4 (X = 0–0.5) soft magnetic materials by low-temperature solid state method

Tin-doped spinel has been reported as a classical soft magnetic material. In this study, series spinels of Fe3-xSnxO4 were synthesized via a novel low-temperature solid-state reaction process from natural magnetite and cassiterite. The substitution mechanisms between Sn4+ and Fe3+ were investigated by means of XRD, TEM, XPS, Mössbauer, FT-IR analysis, etc. The results indicated that the maximum doping stoichiometric content of tin was 0.5 in Fe3-xSnxO4. The substitution occurred prior to proceeding in the octahedral void between Sn4+ and Fe3+, because the ion radius of Sn4+ is very similar to Fe3+ and much smaller than Fe2+. In addition, the effects of tin content on the magnetic properties were revealed. The optimal coercivity value of 10.2 Oe was obtained for Fe2.9Sn0.1O4, which can be used as soft magnetic material. This is related to the lattice distortion caused by Sn4+.

The magnetic properties dependence on temperature of Li-ferrite nanoparticle

The chemical formula Li0.5Fe2.5O4 of lithium ferrite prepared by two different chemical methods mentioned as low temperature solid state reaction (LTSSR) and modified combustion method (MCM). The samples showed nanoparticle scale with spinal structure. The magnetic analyses have done by the vibrating sample magnetometer VSM device, and both samples have the same magnetic properties represented by the magnetic saturation, remanence magnetization, and coercive magnetic field. The shape of hysteresis loop showed a soft ferrite and its area decreased with temperature increasing. On the other hand, the magnetic susceptibility decreased with increasing temperature for both samples of ferrite Li0.5Fe2.5O4 prepared. The sample of LTSSR exhibited a magnetic moment of about 0.410-3 JT-1 at applied magnetic field 50 kOe which is approaching the same for the sample prepared by MCM method.

Influence of rare earth substitution on structure, photoluminescence emission properties and Judd-Ofelt analysis of ZnS:Eu3+ red phosphors

A series of Eu3+ doped ZnS red emitting phosphors were synthesized by conventional low temperature solid state reaction technique. The structural and spectroscopic characteristics of the prepared materials were examined by theoretical and experimental methods. The XRD results confirm the formation of hexagonal structured ZnS material. Similar morphology is obtained from TEM and SEM analysis and the particle size and grain size were calculated. The compositional analysis using EDS confirms the atomic percentage present in the materials. The optical band gap energy of the samples varied from 3.59 to 3.43 eV. The PL emission under excitation 390 nm has greater emission intensity at concentration x = 0.1 in Zn(1-x)S: xEu3+ material. The intense red emission (614 nm) for concentration x = 0.1 have CIE coordinates (0.6090, 0.3905) with color purity 90.41% and CCT 1629.26 K. The site symmetry of Eu3+ ions was explained using PL emission spectra. The intensity parameters Ω2, Ω4 and Ω6, radiative properties like branching ratio (βR), transition radiative parameter (AR), stimulated emission cross section σe, radiative life time (τR) was calculated from Judd-Ofelt theory. The luminescence decay kinetics was analyzed and the life time of material was calculated in millisecond (ms) range. The strong and intense red emission and the improved stimulated emission cross section offer Eu3+ doped ZnS material useful for designing optoelectronic device applications.

Sn4P3-inlaid graphene oxide nanohybrid through low-temperature solid state reactions toward high-performance anode for sodium-ion batteries

Due to nature abundant and low-cost of sodium reserves with broad distribution in the earth's crust, sodium-ion batteries (SIBs) have attracted widespread attention for their great potential application in low-speed electric vehicles and large-scale energy storage system. However, their practical application is still hampered by the lack of decent anode materials. In this work, we develop an effective strategy to fabricate a nanohybrid of Sn4P3 and graphene oxide and demonstrate its outstanding sodium-storage behavior as an anode material for SIBs. By directly grinding tin(IV) chloride pentahydrate, sodium hydroxide, graphene oxide (GO) and surfactant PEG-200 at ambient temperature, an effective solid state reaction occurred to give rise to a precursor (named as SnO2/GO-PEG200), i.e. a nanocomposite of SnO2 encapsulated within GO matrix. After subsequent phosphorization at 280 °C using sodium hypophosphite monohydrate as phosphorous source, a nanohybrid of Sn4P3 and graphene oxide (designated as Sn4P3/GO-PEG200) was acquired. The coexistence of Sn4P3 nanoparticles and GO nanosheets endows the nanohybrid with improved electronic conductivity, highly structural integrity and superior electrochemical performance. When employed as anode material for SIBs, the nanohybrid anode demonstrates a good cycling stability (419 mA h g−1 after 100 cycles at 0.1 A g−1), with a remarkable rate capabilities (325 mA h g−1 at a current density of 1 A g−1 and 187 mA h g−1 at a current density of 5 A g−1, respectively).

Covalent Cross-Linking of Metal-Organic Cages: Formation of an Amorphous Cationic Porous Extended Framework for the Uptake of Oxo-Anions from Water.

Cationic amorphous metal-organic cage (MOC)-based materials capable of removing anionic pollutants from water are receiving increasing attention but they are still relatively less reported. Herein, for the first time, a cationic porous MOC-based extended framework, namely, CL-aMOC-1, was constructed by covalent linking of a cationic Pd12 L24 (L=3,5-di-pyridin-4-yl-benzaldehyde) cage with a 1,4-bis(4-aminophenyl)benzene (BAPB) linker. Interestingly, the reaction could be completed within 15 min using an amorphous MOC-based solid (aMOC-1) and BAPB as reactant via a low-temperature solid-state reaction. The CL-aMOC-1 showed improved stability, lower solubility and higher oxo-anion uptake in water compared with the original aMOC-1. The adsorption capacities for CrO4 2- , Cr2 O7 2- and ReO4 - on CL-aMOC-1 were 245.1, 311.5 and 452.5 mg/g, respectively, in which the uptake of Cr(VI)-containing oxo-anions was among the highest compared with those of other metal-organic materials. The CL-aMOC-1 can selectively capture oxo-anions in the presence of competitive anions. It exhibits good reusability as over 85 % of the uptake capacity is retained after 5 cycles. Finally, it shows the ability to remove Cr(VI) ions from electroplating wastewater.

Fabrication and performance of PNN-PZT piezoelectric ceramics obtained by low-temperature sintering

Abstract The Pb(Ni1/3Nb2/3)O3-Pb(Zr x Ti1−x )O3 (PNN-PZT) piezoelectric ceramics with CuO and LiBiO2 doping were successfully fabricated by the low-temperature solid-state reaction to effectively restrain the PbO volatilization. The microstructure and electrical properties of the PNN-PZT ceramics were characterized. The experimental results reveal that the PNN-PZT ceramics are composed of a pure perovskite structure in which the rhombohedral and tetragonal phases coexist. Meanwhile, the good electric properties, including low dielectric loss, outstanding diffusion phase transition and palpable dielectric relaxation, are exhibited in PNN-PZT ceramics with 0.2 wt.% CuO and 1 wt.% LiBiO2 addition. This piezoceramic composition possibly provides a reference for the application of multi-layer piezoelectric actuators.

Preparation of single-phase YbB6 by low-temperature solid-state reaction method using iodine

In this study, low-temperature solid-state synthesis of pure nanocrystalline ytterbium hexaboride (YbB6) employing iodine-based reduction method has been discussed. For the reduction reaction, the mechanically activated powder mixture of ytterbium oxide, boron oxide, magnesium, and iodine was heated up under Ar in a quartz tube to 85 °C. All reaction byproducts, viz. MgO, Mg3(BO3)2, and YbI2, were removed by hot acid leaching with 3 M HCl solution to form pure YbB6. The morphological and phase structure of the synthesized YbB6 powder were analyzed by X-ray diffractometry (XRD), high-resolution transmission electron microscopy (HRTEM), and Raman spectroscopy. The crystalline phases obtained were refined by multi-phase Rietveld refinement. XRD and Raman spectroscopy showed a contrast between the nano-YbB6 formed by the present low-temperature iodine-based reduction method versus mechanochemical method. The YbB6 produced by the low-temperature iodine reduction method is highly crystalline in nature, whereas YbB6 produced by mechanochemical method is less crystalline or conversely more amorphous in nature. The iodine-based reduction method indeed played a definitive role to allow the reaction to take place at a lower temperature enabling the formation of nanocrystalline YbB6.

Effect of Sc Addition on Magnetic and Optical Properties of YFeO₃ Nano Particles

Multiferroic Sc-doped YFeO₃ nanoparticles were obtained by a low-temperature solid-state reaction route. It indicated that with the addition of Sc, nanosized YFeO₃ powders were obtained at 800 ℃, and the orthorhombic phase was transformed into the hexagonal structure. Magnetic hysteresis loop illustrated the magnetic property of YFeO₃ nanoparticles improved with Sc doping. The maximum magnetization of the powders was about 4.00 emu/g, showing that the energy gap can be reduced to 2.25 eV and thus the doping nanoparticles can be used in optical field. Therefore, the optical and magnetic properties of the material can be obviously enhanced with Sc doping, proving its potential application in magnetic and optical fields.

Magnetoelectric and tunable DC electrical properties of PbZr0.58Ti0.42O3 – Ni0.5Co0.5Fe2O4 multiferroic nanocomposites

The potential properties of the magnetoelectric materials; such as magneto-impedance, magneto-dielectric, irreversibility of current with voltage and magnetoelectric coefficient provide a large research interest in the last few years. We have fabricated PbZr0.58Ti0.42O3 – Ni0.5Co0.5Fe2O4 nanocomposite having a 1:1 wt ratio through the low temperature pyrophoric chemical reaction and solid state reaction techniques. Structural characterization has been carried out through X-ray diffraction technique. We have investigated the magnetically tunable memory effect. The irreversibility in electrical property may be due to the interfacial polarization of the sample. The magnetic field provides a scattering of charge carriers resulting increment of current at a constant applied electric field. Furthermore, a large interfacial polarization of the sample attributes the current in the short circuit condition. Moreover, a large value of magnetoresistance has been found for the nanocomposite and it is ∼54% at a magnetic field of 3 kOe at room temperature.

Efficient Selective Sorption of Cationic Organic Pollutant from Water and Its Photocatalytic Degradation by AlVO₄/g-C₃N₄ Nanocomposite.

This study reports the synthesis, characterization and water remediation application of novel AlVO₄/g-C₃N₄ nanocomposites. The nanocomposite has been synthesized by a low temperature solid-state reaction using graphitic carbon nitride (g-C₃N₄) obtained via calcination of melamine and AlVO₄ prepared via assisted sonochemical technique. Powder X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier Transform Infrared spectroscopy (FTIR), ultraviolet-visible diffuse reflection spectroscopy (UV-vis DRS), and the N₂ gas adsorption Brunauer-Emmett-Teller (BET) method has been used to characterize the pristine and composite samples. AlVO₄ and g-C₃N₄ interact with each other forming a hybrid composite, which shows excellent ability for selective sorption of cationic MB (methylene blue) dye from wastewater. The initial dye concentration, pH and amount of sorbent has been varied and their effect on the adsorption process has been analysed. The photocatalytic efficiency of the MB dye adsorbed pristine g-C₃N₄, AlVO₄:g-C₃N₄ (1:3) and AlVO₄:g-C₃N₄ (1:1) composite has been tested under visible light. With increased proportion of AlVO₄ in the samples, the photocatalytic efficiency improved and the best photodegradation has been observed for the AlVO₄:g-C₃N₄ (1:1) sample. Photoluminescence (PL) studies, photocurrent response measurements and electrochemical impedance spectroscopy (EIS) indicates enhanced separation of the photogenerated electron/hole pairs leading to effective degradation of the MB dye solution in case of the AlVO₄:g-C₃N₄ (1:1) composite sample. The photocatalytic mechanism has been elucidated and it could be inferred that photogenerated holes and superoxide anion radicals play a major role in the photocatalysis process.