Structural and Transport Properties of La0.85Te0.15MnO3 Manganite and its Composite with Al2O3

The manganite systems investigated during the present work are pure La0.85Te0.15MnO3 (LTMO) and its composite with 12% concentration of Al2O3 nano powder (LTMO + Al2O3). The materials were prepared by the modified auto combustion technique. The samples were characterized by X-ray diffraction. The powder X-ray diffraction pattern of pure LTMO at room temperature shows that sample is in single phase with no detectable secondary phases and the sample have a rhombohedral structure in hexagonal with the space group R3c. The XRD pattern of LTMO + 12% Al2O3 indicates the clear presence of Al2O3 nano phase in the composite. In the present study, the FTIR Spectroscopy of both samples was carried out. It is clear from the Vibrational assignment for the value of corresponding peak position of FTIR spectra that no extra unwanted impurity is present in samples. A quantitative analysis of the energy dispersive spectroscopy (EDS) data indicates that the observed concentration of elements are very close to the calculated values from its chemical formula. R-T measurements reveals that the addition of secondary phase in manganite strongly influenced on electronic and magnetoresistance behaviour. We summarise some of the salient features of the results.

Enhanced Energy Storage Density and Excellent Thermal Stability Under Low Electric Fields of KF-added BNT–ST-AN Relaxor Ferroelectric Ceramics Prepared by the Solid-state Combustion Technique

Homogeneous 0.722(Bi0.5Na0.5TiO3)-0.228(SrTiO3)-0.05(AgNbO3) (BNT-ST-AN) ceramics with various amounts of potassium fluoride (KF) added were prepared by the solid-state combustion technique. The ceramics presented a single perovskite phase with coexisting rhombohedral (R), cubic (C) and orthorhombic (O) phases. The amount of the R phase decreased while the percentage of the C+O phase increased when KF addition increased from 0.0 to 3.0 mol%. The smallest grain size, the highest density and maximum dielectric constant (em) were achieved with a KF addition of 1.5 mol%. Following this design composition of the ceramics, the highest recoverable energy-storage density (Wrec ~1.60 J/cm3) and η above 85.8% at a low electric field (100 kV/cm) were obtained from BNT-ST-AN with KF addition at 1.5 mol% because this composition contained a morphotropic phase boundary (MPB) region and had the smallest grain size, which gave the lowest remnant polarization (Pr) and a large maximum polarization (Pm). Additionally, BNT-ST-AN with KF addition at 0.15 mol% exhibits stability over a wide range of temperatures (25–150°C) at a low electric field (100 kV/cm), which shows great potential in pulse-power system applications.

Alcohol Assisted Solution-Combustion Technique for the Synthesis of Phase-Pure BaSnO3 Nanoparticles at 130 °C

Lowering the synthesis temperature to obtain phase pure BaSnO3, which is the host material for high figure-of-merit (FOM) perovskite transparent conductors (TCs), can expand the horizons for its optoelectronic applications, with an obvious reduction in the thermal budget. In this work, we have developed a novel solution combustion technique for the synthesis of BaSnO3 nanoparticles. A peroxo/superoxo precursor to the nanoparticles is first synthesized by co-precipitation of the tin and barium salts via the H2O2 assisted or the `CSMC' route. The phase evolution, under different drying conditions of the wet precursor to crystalline BaSnO3 nanoparticles is then studied. We find that the crystallization temperature of BaSnO3 is significantly reduced by adding an organic solvent such as ethanol or propanol to the precursor; temperatures as low as 130 °C yield phase pure BaSnO3 nanoparticles. We establish that the organic solvent increases the reactive O2 ligand content, which plays a pivotal role in the synthesis. Due to this, an exothermic reaction occurs around 130 °C, thereby providing the heat of reaction for conversion of the precursor to phase-pure BaSnO3. Importantly, this method should also allow for the facile incorporation of dopants, paving the way for synthesis of high FOM TCs at low temperatures. Such low synthesis temperatures enable BaSnO3 to be used in devices having temperature limitations during device processing, such as heterojunction Si solar cells or perovskite-based solar cells in an n-i-p architecture.

Synthesis, Characterization, and NH3 Sensing Properties of (Zn0.7 Mn0.3-x Cex Fe2O4) Nano-Ferrite

This study includes the preparation of novel nano ferrite (Zn0.7 Mn0.3-x Cex Fe2O4) by using the auto combustion technique. For the following molar values, the percentage x was calculated: 0.0, 0.05, 0.1, 0.15, 0.2, 0.25, and 0.3. The nano-ferrite was calcined for 2 hours at 500°C. The energy dispersive x-ray spectroscopy (EDX), X-ray diffraction (XRD) and field emission scanning electron microscopy FE-SEM was used to examine structural, morphological, and sensing properties. The spinel cubic structure was revealed by XRD findings. The particle distribution was shown to contain voids by FE-SEM. The testing of sensing characteristics to NH3 gas indicated that the synthesized nano-ferrite has a small response time ranging from (15.3-25.2) s as well as a small recovery time between (36-58.5) s, also has a higher sensitivity of about 72.23%.

Albumen-mediated Green Synthesis of ZnFe2O4 Nanoparticles and Their Physico-Chemical Properties

Spinel ferrites with general formula AB2O4 possess charming magnetic and electrical properties owing to their thermal and chemical steadfastness. Spinel zinc ferrite (ZnFe2O4) nanoparticles have attracted massive attention due to their unusual amalgamation of properties, especially magnetic properties, where these properties are equipped as suitable candidates in the field of electronics. Here, a simple self-combustion technique is made with the assistance of albumen to synthesize nanocrystalline zinc ferrite (ZnFe2O4) particles. The egg white (albumen) that is used in the synthesis process plays the fuel role in the process of combustion. The results of the powder X-ray diffraction (PXRD) and Fourier Transform Infrared Spectroscopy (FTIR) suggested that the synthesized nanoparticles are of single phase and show spinel structure. The photoluminescence studies reported a doublet peak at around 360-380 nm. The functional groups present in the synthesized nanoparticles were revealed from FTIR data. EDX findings give an account of the percentage composition of the elements Fe, Zn and O present in the synthesized sample. High-resolution Scanning Microscope (HRSEM) reveals the agglomerated coalescence nature of ferrite nanoparticles. Keywords: Ferrite, PXRD, FTIR, HRSEM, EDX Albumen.

The preparation of Li7La3Zn2O12(LLZO) battery ceramic and its conductivity

For Li7La3Zr2O12 (LLZO) solid electrolytes, higher density usually means higher ionic conductivity. Researchers tried many preparation methods to get high density samples and at same times to realize industrial production, low cost, scalable and fast synthesis techniques. In this paper, the mainstream preparation methods of LLZO was given, as polymerized complex method, sol-gel method, field assisted sintering, combustion technique, auto-consolidation method, water-based solvent method. Among these methods, the last four methods can always increase the density to more than 93%. Especially the field assisted sintering method can make the relative density to be high as 99.8%. And all of these methods can make the ion conductivity to be higher than 1.4 × 10-4 S cm-1. Also, most of these methods introduced the Al element into LLZO to realize the liquid sintering.

Dosimetric applications of CdSiO3 nanoparticles prepared via Solution Combustion Technique

Pure CdSiO3 nanoparticles have been prepared by a solution combustion technique. The powders were well characterized by powder X-ray diffraction, Field Emission scanning electron microscopy and Ultra Violet-visible spectroscopy. The powder X-ray diffraction peaks of as-formed sample are broad and amorphous in nature; therefore it is further calcined at 800 oC for 2 h and its powder X-ray diffraction results shows that the sample had a good crystallization with Single phase. Debye- Scherer’s formula and Williamson–Hall plots are used to calculate the average crystallite size and found to 32-43 nm. The Scanning electron microscope and Transition electron microscope results reveal that the pure CdSiO3 nanoparticles were porous and agglomerated with irregular nanopowder. The absorption peaks for pure CdSiO3 nanoparticles were found to about 256 nm as observed in Ultra Violet-Visible spectra. The structural defects present in the material band gap (Eg) value were 5.6 eV. A well resolved thermoluminescence glow peaks in the range of (110-160) oC are observed in UV-irradiated pure CdSiO3 nanoparticles. Glow peak at 160 ºC was seen and Thermoluminescece intensity increases linearly with Ultra Violet dose in the samples. The kinetic parameters were determined by Halperin – Braner, Luschik and Chen’s methods. De-convolution of pure CdSiO3 nanoparticles exposed to Ultra Violet dose (UV dose: 30 min) was used for the estimation of kinetic parameters. Hence in pure CdSiO3 nanoparticles presence of deep traps recommends that the prepared sample may be used as a radiation dosimeter.