Impact Of Sintering Temperature Research Articles

The impact of sintering temperature on microstructure, optical and thermal properties of SnO2 ceramics

The impact of sintering temperature on microstructure, optical and thermal properties of SnO2 ceramics

Effect of sintering temperature on magnetic, catalytic and photocatalytic properties of Cu-Co-Mn ferrite catalyst

Wastewater pollution is a pressing environmental issue, necessitating effective remediation strategies to mitigate its impact. This study investigates the use of an efficient catalyst for degrading nitrophenols by converting them into useful aromatic amines, which are crucial building blocks for many pharma industries, and photodegradation of various dyes in their unitary solution as well as in mixture. The Cu-Co-Mn ferrite was synthesized using the sol-gel process and sintered at different temperatures. Structural analysis using XRD and Rietveld refinement revealed a crystal structure corresponding to the Fd3‾m space group having high purity in all the samples. Additionally, the impact of sintering temperature on the magnetic features of the phases were also studied and the findings suggest that all the phases exhibit ferromagnetic behaviour, which means they can be easily separated from reaction mixtures using an external magnetic field. It was also found that higher sintering temperatures lead to a rise in saturation magnetization and magnetic moment with decrease in coercivity (Hc). Further, it was observed that Curie temperature (Tc) increases with increase in sintering temperature with the exception of CFM400. The catalytic performance of all the catalysts, including CFM400, CFM500, CFM600, CFM800, and CFM1000, was evaluated and the results indicate that CFM400 exhibits the highest catalytic activity for nitrophenols reduction and photodegradation of dyes, which could be accredited to its larger BET surface area and lower PL intensity. Overall, the structural and magnetic features of the catalyst’s sheds light on the underlying mechanisms governing their catalytic activity. These insights offer valuable guidance in the designing and development of effective catalysts for sustainable wastewater treatment practices, emphasizing the importance of considering both structural and magnetic features in catalyst design.

Hydrogen generation by water splitting of formic acid assisted supramolecular self-assembled g-C3N4 nanostructures

The photocatalytic hydrolysis reaction primarily unfolds on the material's surface, making the material's morphology and microstructure critical for the catalytic efficiency of photocatalysts. In this paper, a formic acid-assisted melamine hydrothermal self-assembly method is explored to prepare g-C3N4 photocatalysts with a unique morphology. The impact of sintering temperature on the morphology of the g-C3N4 photocatalysts are explored and the effect of formic acid concentration on the XRD and FTIR was analyzed. Findings reveal that the g-C3N4 nanostructures photocatalyst possesses fibrous tubular and nanosheet structures, boasting a heightened specific surface area (32.9 m2/g) and a more refined graphite-like crystalline framework. When synthesized with a 0.15 M concentration of formic acid, the g- C3N4 nanostructured photocatalyst achieved a hydrogen production rate (1289.4 μmol h−1 g−1), which is approximately 4.8 times greater than that of bulk g-C3N4 (264.7 μmol h−1 g−1). This work provides a simple method for preparing high-performance g-C3N4 based photocatalysts for visible light hydrolysis hydrogen production.

Study of Lightweight Ceramic Matrix-Less Syntactic Foam Composed of Cenosphere Using Spark Plasma Sintering.

The current investigation presents porous ceramic materials prepared with cenospheres (CS) by using spark plasma sintering. The impact of sintering temperature, mould diameter (20, 30 and 50 mm) and cenosphere size on the properties of the sintered material was investigated. Shrinkage of the samples during sintering started at 900 °C. Total sample shrinkage during sintering increases with increasing temperature and decreases with increasing mould size; increasing sample sintering temperature increases the apparent density of all sample series CS 63-150 µm in a 20 mm mould from 0.97 to 2.3 g·cm-3 at 1050-1300 °C; in a 30 mm mould, 0.81-1.87 g·cm-3 at 1050-1200 °C; in 50 mm mould, 0.54-0.75 g·cm-3 at 1050-1150 °C; while CS 150-250 µm in a 20 mm mould is 0.93-1.96 g·cm-3 at 1050-1200 °C. Total porosity decreases from 61.5% to 3.9% by increasing sintering temperature from 1050 to 1250 °C, while open porosity reduces at lower temperatures, with closed porosity being highest in samples sintered at 1150 °C. When the sintering temperature increases from 1050 to 1300 °C, the compressive strength of the CS 63-150 samples produced in a 20 mm mould increases from 11 MPa to 312 MPa. These results correlate with the Rice model, which describes an exponential dependence of compressive strength on material porosity and fully dense material compressive strength.

High-entropy (Co0.2Mn0.2Fe0.2Zn0.2Al0.2)3O4 thick-film NTC thermistor with high aging stability and wide temperature measurement range

Here, a novel type of high-entropy (Co0.2Mn0.2Fe0.2Zn0.2Al0.2)3O4 solid-solution ceramics with spinel phase structure was designed and successfully fabricated based on an entropy engineering approach. Additionally, the impact of sintering temperature, a critical factor in entropy stabilization, on structural and electrical behavior was systematically examined at a range of 1110∼1150 °C. The results indicate that each synthesized sample exhibits a single spinel structure in the Fd‾3 m (227) space group, and all five metal elements were uniformly distributed, demonstrating entropy stabilization. Meanwhile, the fabricated high-entropy ceramics manifest exceptional negative temperature coefficient (NTC) characteristics in the temperature range of 25 °C–350 °C. The aging stability is excellent as well. After aging at 150 °C for 1000 h, the ΔR/R0 of thick-film samples sintered at 1150 °C is less than 1 %. The successful synthesis of this novel class of spinel-type high-entropy ceramics introduces an emerging design approach for the development of NTC thermistors, particularly for applications in medium-temperature environments.

Effect of sintering temperature on impedance and EMI shielding of carbon modified CoFe2O4 nanofibers via electrospinning

The electrospinning technique is employed for the synthesized cobalt ferrite/carbon nanofibers, utilizing iso-propanol as the solvent. The nanofibers prepared are subjected to sintering at three different temperatures. A comprehensive analysis is carried out on the structural, morphological, dielectric, impedance, and electromagnetic shielding effectiveness within the X-band frequency range (8.2–12.4 GHz). The application of the Debye-Scherer formula yielded an estimated crystallite size of 22 nm. The electrical response of cobalt ferrite/carbon nanofibers pellet is characterized by employing impedance spectroscopy. Variations in impedance plane plots are discussed based on frequency dependent relaxation time modulations. The impact of sintering temperature is observed in terms of increased impedance values and modifications in the conduction mechanism. These changes are contributed to distinct hopping carriers’ linkages between Fe3+-Fe2+ and Co3+-Co2+ ions. Dielectric studies are elucidated considering cation polarizability, colossal resistivity, and tangent loss. This study revealed notable characteristics of CoFe2O4/C nanofibers, including colossal resistivity (8.45 × 108 Ωcm), a dielectric constant of 22, and colossal tangent loss. The CoFe2O4/C nanofibers exhibit a characteristic electromagnetic interference (EMI) shielding performance of 30–35 dB. This remarkable shielding performance is observed in nanofibers with a 3 mm thickness, specifically in sample S1 that underwent sintering at a low temperature. The shielding effectiveness is demonstrated within the X-band frequency range.

Controlled Synthesis and Visible-Light-Driven Photocatalytic Activity of BiOBr Particles for Ultrafast Degradation of Pollutants.

For the purpose of regulating the visible-light-driven photocatalytic properties of photocatalysts, we selected BiOBr as the research target and various routes were used. Herein, via the use of a hydrothermal method with various solvents, BiOBr particles with controllable morphology and photocatalytic activities are obtained. In particular, through changing the volume ratio of ethylene glycol (EG) to ethanol (EtOH), BiOBr compounds possess microspheres, in which samples synthesized by using EG:EtOH = 1:2 have the highest photocatalytic activity, and can completely decompose RhB under visible light irradiation within 14 min. Furthermore, we also used different volume ratios of EG and H2O reaction solvents to prepare BiOBr particles so as to further improve its pollutant removal ability. When the volume ratio of EG to H2O is 1:1, the synthesized BiOBr particles have the best photocatalytic activity, and RhB can be degraded in only 10 min upon visible light irradiation. Aside from the reaction solvent, the impact of sintering temperature on the photocatalytic properties of BiOBr particles is also explored, where its pollutant removal capacities are restrained due to the reduced specific surface area. Additionally, the visible-light-triggered photocatalytic mechanism of BiOBr particles is determined by h+, ·OH and ·O2- active species.

Impact of sintering temperature and ascertaining hopping bottlenecks for ions in sodium superionic conducting electrolyte for sodium-ion batteries

Recently, sodium super-ionic conducting (NASICON) type solid electrolytes have gained attention for next generation batteries because of their high ionic conductivity, low cost, excellent chemical and electrochemical stability. Therefore, in the present study, NASICON-type solid electrolyte Na3Zr2Si2PO12 is synthesized by solution assisted-solid state reaction (SA-SSR) route. The electrolytes are sintered at three different temperatures, 1200 °C, 1250 °C and 1300 °C. The sintered electrolytes are characterized by various experimental techniques. The Rietveld refinement of X-ray diffraction pattern of prepared electrolytes revealed the monoclinic crystal structure. The 3-dimension hopping channel for sodium ion migration through triangular bottleneck area is identified. From complex impedance spectroscopy measurement, the highest bulk and grain boundary conductivity are found, ∼4.05mScm−1 and ∼0.31mScm−1, respectively, for the sample sintered at 1250 °C. The optimized electrolyte shows wide electrochemical stability (∼6.5 V) which is suitable for high voltage battery application. Using optimized electrolyte, sodium half-cell is fabricated with sodium metal as anode, and Na3V2P3O12 (NVP) as cathode. The assembled cell delivers maximum discharge capacity ∼101.6 and ∼84.5mAhg−1 at the current density 10 and 40mAg−1, respectively with good capacity retention (∼95.02%) upto 50 cycles.

Impact of sintering temperature on the structural, magnetic and magnetocaloric properties in La0.75Eu0.05Sr0.2MnO3 manganite

This work concerns a profound study on the structural, magnetic properties and the influence of gradual decrease of the sintering temperature TS on the magnetocaloric properties of La0.75Eu0.05Sr0.2MnO3 manganite elaborated by adopting sol-gel method with TS = 800 °C, 1000 °C and 1200 °C. The refinement of X-ray diffraction patterns at room temperature has shown the coexistence of both rhombohedral R3¯c and orthorhombic Pnma structural phases. The grain size of the sample sintered at 800 °C is around 56 nm. The Curie temperature TC slightly shifts from 305 K to 298 K with decreasing particle size. The magnetic behavior has been discussed based on the core-shell structure. Reducing TS induces the broadening of the magnetic transition. According to the magnetocaloric study, the maximum relative cooling power (RCP) value was recorded for the sample sintered at 800 °C (RCP = 90.11 J/kg for a magnetic field of 2 T at 298 K) suggesting that this sample represents a promising candidate for magnetic refrigeration at room temperature.

The impact of sintering temperature on the thermoelectric performance of Cu2Se synthesized by solid state reaction method

In this study, copper selenide (Cu2Se) compounds were synthesized using a solid-state reaction technique and post-sintering processes (573 ​K–973 ​K). The mass density of the Cu2Se compounds decreased with increasing sintering temperatures due to changes in grain morphology and an increase in the number and size of pores in the samples. The sintering temperature also affected carrier generation mechanisms, which directly impacted the electrical transport characteristics and thermal properties. The α→β phase transition at around 400 ​K was observed in all samples. The low thermal conductivity was mainly attributed to the low lattice thermal conductivity (κlattice). As the result, the sample sintered at 773 ​K showed an outstanding ZT value of 1.44 ​at 773 ​K, with a power factor of 12.1 μWm−1K−2 and the thermal conductivity of 0.65 Wm−1K−1. The sintering temperature dependence of thermal conductivity was elucidated in terms of the growth of microstructural pores.

Investigation on effect of sintering temperature on structural, morphological and magnetic properties of pure and tin doped nickel ferrites for soft magnetic device applications

Based on the importance of the understanding of the ferrite material properties at high temperature conditions, the present authors made re-investigation for pure and tin doped nickel ferrite materials at sintering temperature conditions such as 900 to 1200°C with 100 deg interval. Crystallographic phase stability and grain size effects of pure and doped test samples with respect to temperature are evaluated by powder X-ray diffractometer (PXRD). Surface morphology and magnetic phase stabilities are details are examined by the scanning electron microscope (SEM) and vibrating sample magnetometer (VSM). Fortunately, 1200 deg/C sintered pure and tin doped title material showed the good crystalline nature and high statured saturation magnetization compared to other samples due to the re-crystallization effect taking place by the impact of sintering temperature. The triangle correlation of structural – morphological- magnetic properties is discussed.

Impact of sintering temperature on H2TiO3 lithium-ion sieves synthesised via the solid-phase method

Impact of sintering temperature on H2TiO3 lithium-ion sieves synthesised via the solid-phase method

Impact of sintering temperature on phase composition, microstructure, and porosification behavior of LTCC substrates

Phase development and changes in crystalline composition of LTCC material during the sintering process were investigated using in-situ X-ray diffraction (XRD) measurements. CeramTape GC was chosen as the chemically simplest model system composed of alumina particles and glass for the investigations. The chemical characterization and microstructural analyses of the tapes sintered with some representative firing profiles were performed by techniques such as (scanning) transmission electron microscope, energy-dispersive X-ray spectroscopy, Raman spectroscopy, X-ray photoelectron spectroscopy, and XRD. Moreover, the porosification behavior of LTCC substrates fired at different peak temperatures was studied. These investigations are important for the subsequent wet chemical etching, representing an approach which allows to reduce locally the permittivity of LTCC tapes. Treatment with a KOH solution shows non-selective etching behavior for all substrates. In addition, highly porous silica structures corresponding to Ca and Al depletion from the anorthite phase were observed in all samples after etching treatment.

Indigenous bentonite based tubular ceramic microfiltration membrane: Elaboration, characterization, and evaluation of environmental impacts using life cycle techniques

This work fabricated a tubular ceramic microfiltration membrane from local bentonite clay and further characterized it to evaluate the membrane properties. The extrusion method followed by sintering was used to prepare the membrane. Rice husk ash (RHA) and activated charcoal were added as additives to improve the mechanical stability and porosity of the membrane. The synthesized tubular-shaped membrane was 100 mm in length, and it has 10 mm outside diameter and 5 mm inside diameter. X-ray diffraction and thermogravimetric and differential thermal analysis techniques were used to characterize the raw materials. The resulting bentonite membrane was analyzed by field emission scanning electron microscopy, mechanical strength, porosity, pure water flux, permeability, and pore size. In addition, the impact of sintering temperature on membrane properties was extensively studied. The membrane sintered at a temperature of 900 °C possesses a good porosity of 37% and exhibited an excellent flexural strength of 18 MPa. Besides, the membrane has shown better corrosion resistance towards acidic and basic environments. Permeability of the elaborated membrane was identified as 5.805 × 10−8 m3/m2 s kPa from pure water flux measurements, and its average pore size was estimated as 0.11 μm. Therefore, the prepared low-cost ceramic membrane could be predictable as a promising applicant for microfiltration applications due to its remarkable properties. The fabrication cost of the prepared tubular ceramic membrane was calculated as 96 $/m2. In addition, the environmental impacts of the fabricated membrane were assessed using GaBi ts 9.5.2.49 Pro software. It was observed that the majority of the impacts were primarily due to the power consumed during fabrication, and moving away from the conventional source of energy (fossil fuels) significantly (92.9%) reduced the impacts.

Impact of Sintering Temperature on the Electrical Properties of La0.9Sr0.1MnO3 Manganite

La0.9Sr0.1MnO3 nanoparticles were prepared using the citrate–gel route and sintered at different temperatures (TS = 600 °C, 800 °C, and 1000 °C). The x-day diffraction patterns reveal that the samples exhibit a single phase with a rhombohedral (R3¯C) structure. The transmission electron microscopy technique shows an increase in the grain size when the sintering temperature (TS) rises. The obtained values are approximately similar to that of crystallite size calculated from x-ray diffraction patterns. The impact of sintering temperature (TS) on the electrical properties of La0.9Sr0.1MnO3manganite is examined using the impedance spectroscopy technique. A metal-semi-conductor transition at a specific temperature (TM-SC) is observed for all samples. Indeed, the sintering temperature increase induces the shift of this transition temperature toward higher temperatures. Such a behavior is explained by the increase in the grain size. An agreement between the metal-semi-conductor transition values coming from the DC resistivity and the grain boundaries analyses is observed. This agreement proves the contribution of the grain boundaries in the electrical properties of the studied samples. In addition, the presence of the relaxation phenomenon is confirmed. The fitted Nyquist plots show the correlation between the microstructure of the material and the electrical properties using an electrical equivalent circuit model. The DC resistivity and the impedance analyses reveal the thermal activation of the transport properties in the investigated system.

Mechanical properties and microstructure of spark plasma sintered Al2O3-SiCw-Si3N4 composite ceramic tool materials

In this study, Al2O3-SiCw-Si3N4-based ceramic tool materials were fabricated by spark plasma sintering technique. The impact of sintering temperature on mechanical properties and local microstructure was thoroughly investigated. Moreover, detailed comparison was performed between spark plasma sintering and early hot-pressing sintering methods. Evolution law and mechanism of high-temperature mechanical properties were also investigated. Composites with higher density and enhanced mechanical properties were obtained by spark plasma sintering at temperature of 1500 °C, which was 100 °C lower than hot-pressing temperature. The cross-interlocking structure of generated β-Sialon particles and silicon carbide (SiC) whiskers could effectively improve mechanical properties of material configuration. Moreover, Vickers hardness and fracture toughness of ceramic composites decreased by elevating temperature (20–1000 °C); however, following percentages at 1000 °C were still maintained with respect to values at room temperature, i.e., 67 and 51%. This effect is attributed to existence of Sialon phase, healing of partial cracks, as well as manifestation of whisker pullout process. As a result, decreased attenuation rate under high-temperature conditions of respective mechanical properties was observed. Our approach provides useful insights into potential fabrication of novel material configurations with relatively low thermal budget and enhanced mechanical performance.

High-conductivity flexible Ag films formed by low-temperature and short-time sintering of PVP-modified silver oxalate composite ink

Attaining low-temperature sintering and high electrical conductivity is vital in the field of flexible electronics. Inks with silver oxalate as the precursor have recently received significant attention in this field; however, the high sintering temperature and long sintering time limit commercial applicability. High sintering temperature can shorten the sintering time but lead to porous and uneven film morphology; thus, reducing the conductivity. On the other hand, low sintering temperature prolongs the sintering time; thus, reducing the production efficiency. To solve the abovementioned problems, a silver composite conductive ink modified by polyvinylpyrrolidone (PVP) was prepared in this study. The ink used silver oxalate as the precursor, methanol and acetone as the solvent, and 1, 2-diaminopropane as the complexing agent, and could reduce the sintering temperature and time to 160 °C and 20 min, respectively. After sintering, the silver film showed good electrical conductivity, and low resistivity (4.56 μΩ·cm). Furthermore, the impact of sintering temperature on the surface morphology and electrical conductivity were also studied, and the results showed that PVP had a positive influence on the nucleation of silver and the microstructure of the sintered silver film.

Synthesis and characterization of manganese ferrite from low grade manganese ore through solid state reaction route

Manganese ferrite spinel has been synthesized by using low grade manganese ore and ferric oxide as sources of manganese oxide and iron oxide through solid state reaction route by taking manganese and iron mole ratio of 1:2 respectively. The impact of sintering temperature on phase composition and particle size is investigated. Similarly, the impact of frequency on dielectric constant, dielectric loss, AC (alternating current) conductivity and tangent losses is also investigated. The results shows the presence of spinel structure manganese ferrite (MnFe2O4) as the major phase for the sample sintered at 1200 °C. It has been established that the crystallite size increase with rise in sintering temperature. The surface morphology of the sample sintered at 1200 °C show pyramidal and triangular shape grains. The dielectric constant (εʹ) and dielectric losses (εʹʹ) were observed to decrease with increasing the sintering temperature and frequency. Furthermore, the AC (alternating current) conductivity was found to rise with rise in applied frequency. On the other hand, the tangent losses falls considerably with rise in applied frequency.

Impact of Sintering Temperature on Crystallite size and Optical Properties of SnO2 Nanoparticles

Tin oxide (SnO2) nanoparticles synthesized by hydrothermal method and kept at sintering temperatures (800-1200 ºC). The tin (II) chloride dehydrate (SnCl2.2H2O) used to prepared the SnO2 precursor solution. The Tin oxide nanoparticles have been characterized by X-ray diffraction (XRD), Field emission scanning electronic spectroscopy (FESEM), and UV-Visible spectroscopy. The nanoparticles size of SnO2 depends on the degree of sintering temperature, it found crystallite size (22.12,27.34 , 36.11 and 42.02) nm of the SnO2 at800, 900, 1000 and 1200°C, respectively. XRD shows a pure tetragonal rutile crystalline structure for SnO2 nanoparticles. FESEM images revealed the particles size increased with increasing sintering temperature. The transmittance and absorption are affected by an increased degree of sintering temperature. The band gap of SnO2 nanoparticles decreased with increasing sintering temperature (2.6 to 2.4) eV when temperature raised from 800 to 1200 ºC, which belongs to the effect of particle size

COMPOSITE Cu-Cr MATERIALS UNDER THERMAL ACTION OF ELECTRIC ARC DISCHARGE PLASMA

The results of optical emission spectroscopy (OES) investigation of plasma of electric arc discharges in steadystate mode between Cu-Cr composite electrodes, manufactured at different sintered temperatures: 750, 850, 950 or 1050 °C, is presented. In particular, the impact of sintering temperature on erosion resistanceof such composite materials, which was determined in indirect manner by estimation of metal vapours content in the midsection of discharge gaps, is studied by the analysis of plasma parameters. These contents were calculated in assumption of local thermodynamic equilibrium (LTE) on the base of experimentally obtained radial distributions of plasma temperature and electron density.