scholarly journals Magnetic Properties of La0.9A0.1MnO3 (A: Li, Na, K) Nanopowders and Nanoceramics

Materials ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1788
Author(s):  
Paweł Głuchowski ◽  
Ruslan Nikonkov ◽  
Robert Tomala ◽  
Wiesław Stręk ◽  
Tatsiana Shulha ◽  
...  
Keyword(s):  
Combustion Method ◽  
Magnetic Characteristics ◽  
X Ray ◽  
Alkali Ions ◽  
Structure And Morphology ◽  
Ceramic Samples ◽  
High Pressure Sintering ◽  
The Impact ◽  
Sintering Method ◽  
Scanning Electron

Nanocrystalline La0.9A0.1MnO3 (where A is Li, Na, K) powders were synthesized by a combustion method. The powders used to prepare nanoceramics were fabricated via a high-temperature sintering method. The structure and morphology of all compounds were characterized by X-ray powder diffraction (XRD) and scanning electron microscopy (SEM). It was found that the size of the crystallites depended on the type of alkali ions used. The high-pressure sintering method kept the nanosized character of the grains in the ceramics, which had a significant impact on their physical properties. Magnetization studies were performed for both powder and ceramic samples in order to check the impact of the alkali ion dopants as well as the sintering pressure on the magnetization of the compounds. It was found that, by using different dopants, it was possible to strongly change the magnetic characteristics of the manganites.

The Research on High Pressure Sintering of Mixed Powder γ-Si3N4 and α-Si3N4

2011 ◽  
Vol 284-286 ◽  
pp. 1397-1400
Author(s):  
Huai Yao ◽  
Yong Zhi Wang ◽  
Bo Xu
Keyword(s):  
Electron Microscopy ◽  
High Pressure ◽  
Cross Sections ◽  
X Ray Diffraction ◽  
Mixed Powder ◽  
Sintered Ceramic ◽  
X Ray ◽  
Ceramic Samples ◽  
High Pressure Sintering ◽  
Scanning Electron

The high pressure and high temperature sintering of α-Si3N4 and γ-Si3N4 with Y2O3-Al2O3-La2O3 as additives were studied under pressures of 5.4 GPa and temperatures of 1420-1770 K. The effects of sintering temperatures and pressures on properties of sintered ceramic samples were investigated with X-ray diffraction and scanning electron microscopy. The results show that γ-Si3N4 and α-Si3N4 is transformed to β-Si3N4 completely. The highest relative densities and Vickers hardness (HV) of sintered samples are 98.71 and 21.76GPa, respectively. The sintered samples were composed of elongated β-Si3N4 rod crystals with disordered orientation and had intergranular interlocks and uniform and compact microstructure. Pulled out crystal grains on the fractured cross sections were obviously observed by SEM.

scholarly journals Ferroelectromagnetic Properties of PbFe1/2Nb1/2O3 (PFN) Material Synthesized by Chemical-Wet Technology

Materials ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 2504 ◽  
Author(s):  
Dariusz Bochenek ◽  
Przemysław Niemiec
Keyword(s):  
Magnetic Properties ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Sintering Temperature ◽  
Closed Porosity ◽  
X Ray ◽  
Synthesis Conditions ◽  
Ceramic Samples ◽  
Sem Microstructure ◽  
Scanning Electron

In this work, PbFe1/2Nb1/2O3 (PFN) ceramic samples synthesized by chemically wet method (precipitation from the solution) were obtained. Due to the tendency to form powder agglomerates, the synthesized powder was subjected to ultrasound. The sintering was carried out under various technological conditions, mainly through controlling the sintering temperature. -X-ray powder-diffraction (XRD), scanning electron microscope (SEM) microstructure analysis, as well as the examinations of dielectric, ferroelectric, and magnetic properties of the PFN ceramics were carried out. Studies have shown that hard ceramic agglomerates can be partially minimized by ultrasound. Due to this treatment, closed porosity decreases, and the ceramic samples have a higher density. Optimization and improvement of the technological process of the PFN material extends the possibility of its use for the preparation of multiferroic composites or multicomponent solid solutions based on PFN. Such materials with functional properties find applications in microelectronic applications, e.g., in systems integrating ferroelectric and magnetic properties in one device. The optimal synthesis conditions of PFN ceramics were determined to be 1050 °C/2 h.

Characteristic of a Novel Composite Inorganic Polymer Coagulant-PAZF Prepared from Industrial Wastes

2014 ◽  
Vol 977 ◽  
pp. 82-85
Author(s):  
Ming Li ◽  
Yan Zhen Yu ◽  
Juan Ting Wang
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Complex Compounds ◽  
Industrial Wastes ◽  
X Ray Diffraction ◽  
X Ray ◽  
Structure And Morphology ◽  
Coagulation Performance ◽  
Composite Coagulant ◽  
Scanning Electron

A new composite coagulant polymeric aluminum zinc ferric (PAZF) was synthesized from industrial wastes. The structure and morphology of the coagulant was characterized by X-ray Diffraction (XRD), Infrared Spectroscopy (IR) and Scanning Electron Microscopy (SEM) and the coagulation performances were evaluated by dyeing-printing wastewater treatment. The results show that new complex compounds are formed in PAZF. Compared with poly aluminum chloride (PAC), the contents of ionic polymerized bonds and the cross-copolymerization among Fe (III), Al (III) and Zn (II) hydroxyl polymerized bonds are increase obviously, and the surface morphology of PAZF presents a net-like structure with the longer molecular chain. Coagulation experiments indicate that PAZF exhibits better coagulation performance in removing turbidity, COD and chromaticity.

scholarly journals Structure and Morphology Properties of Nanoparticle Hematite Pigment from Lathe Waste

2021 ◽  
Vol 13 (1) ◽  
pp. 21
Author(s):  
Lilik Miftahul Khoiroh ◽  
Asmaul Dwi Ayu Sholekah ◽  
Eny Yulianti
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Diffraction Data ◽  
X Ray Diffraction ◽  
Crystallinity Degree ◽  
X Ray ◽  
Structure And Morphology ◽  
Calcination Method ◽  
Scanning Electron ◽  
Color Reader

Hematite coated PEG was synthesized by the sonication-calcination method. A variation of Na2CO3 is investigated to know the effect on structure and morphology. Characterization of samples are using X-ray fluorescence, X-ray diffraction, Scanning electron microscopy, and color reader techniques. XRF data showed that iron is the highest element in the precursor. The X-ray diffraction data confirm that Fe(OH)3, α-FeOOH, and Fe3O4 established at the sonication stage are then transformed into the α-Fe2O3 phase after calcination. The X-ray diffraction data also was found that α-Fe2O3 at 0.5 M formed with the highest crystallinity degree. The scanning electron microscopy showed that the particle's shape is spherical, bar-shaped, and aggregate. However, the distribution of particles is not uniform and still displays agglomeration. The Color reader shows the highest degree of lightness obtained is at 1 M variation.

Preparation and Microstructure of Pressureless Sintered Si2ON2-SiC Ceramic

2011 ◽  
Vol 335-336 ◽  
pp. 699-703
Author(s):  
Hui Hui Tan ◽  
Zhu Xing Tang ◽  
Xia Zhao ◽  
He Zhang
Keyword(s):  
Bulk Density ◽  
Sintering Temperature ◽  
Pressureless Sintering ◽  
Nitriding Temperature ◽  
X Ray Diffraction ◽  
X Ray ◽  
Effect Of Additives ◽  
Sic Ceramic ◽  
Sintering Method ◽  
Scanning Electron

This paper introduces Si2ON2-SiC ceramic fabricated by pressureless sintering method and studies the effect of additives, nitriding temperatures on bulk density, porosity, phase composition and microstructure. It is discovered that additives MgO, CeO2 can increase the densities of Si2ON2-SiC ceramic apparently, and MgO additive has a better effect than CeO2. Nitriding temperature also is an important factor. The bulk density of the specimen with MgO additive reaches maximum at 1.91 g/cm3 when sintered at 1450 °C, and the bulk density of specimen with CeO2 additive is 1.86 g/cm3 at the same condition while the bulk density of the specimen without additive is only 1.75 g/cSuperscript textm3. The X-ray diffraction and scanning electron microscopy of the specimens show that the amount of Si2ON2 increase with the sintering temperature increase. But when the temperature is higher than 1500 °C the Si2ON2 grains will decompose into Si3N4, and Si2ON2 will vanish at 1550 °C

SYNTHESIS, MORPHOLOGY AND STRUCTURAL PROPERTIES OF (GD,ND)SR2RUCU2O8 SAMPLES

2003 ◽  
Vol 17 (04n06) ◽  
pp. 899-904 ◽  
Author(s):  
A. VECCHIONE ◽  
M. GOMBOS ◽  
C. TEDESCO ◽  
A. IMMIRZI ◽  
L. MARCHESE ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Solid State ◽  
Powder Diffraction ◽  
Solid State Reaction ◽  
X Ray ◽  
Structure And Morphology ◽  
Polycrystalline Powder ◽  
Scanning Electron

NdSr 2 RuCu 2 O x material has been prepared as polycrystalline powder by solid state reaction. The compound has been investigated by synchrotron x-ray powder diffraction and scanning electron microscopy. The experimental results show that the average crystal structure is a disordered cubic perovskite with Nd and Sr cations occupying the same site and the same substitution is found for Cu and Ru atoms. A comparison between the crystal structure and morphology of this compound and the superconducting tetragonal GdSr 2 RuCu 2 O 8 is also discussed.

Effect of Dip-Coating Cycle on Some Physical Properties of Cu2NiSnS4 Thin Films for Photovoltaic Applications

2021 ◽  
Author(s):  
Ahmed ZITI ◽  
Bouchaib HARTITI ◽  
Amine BELAFHAILI ◽  
Hicham LABRIM ◽  
Salah FADILI ◽  
...  
Keyword(s):  
Thin Films ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Sol Gel ◽  
Dip Coating ◽  
Visible Spectroscopy ◽  
X Ray ◽  
Uv Visible ◽  
The Impact ◽  
Scanning Electron

Abstract Quaternary semiconductor Cu2NiSnS4 thin film was made by the sol-gel method associated to dip-coating technique on ordinary glass substrates. In this paper, we have studied the impact of dip-coating cycle at different cycles: 4, 5 and 6 on the structural, compositional, morphological, optical and electrical characteristics. CNTS thin films have been analyzed by various characterization techniques including: X-ray diffractometer (XRD), Raman measurements, scanning electron microscope (SEM), energy dispersive X-ray spectroscope (EDS), UV-visible spectroscopy and four-point probe method. XRD spectra demonstrated the formation of cubic Cu2NiSnS4 with privileged orientation at (111) plane. Crystallite size of cubic CNTS thin films increase with from 6.30 to 9.52 with dip-coating cycle augmented. Raman scattering confirmed the existence of CNTS thin films by Raman vibrational mode positioned at 332 cm− 1. EDS investigations showed near-stoichiometry of CNTS sample deposited at 5 cycles. Scanning electron microscope showed uniform surface morphologies without any crack. UV-visible spectroscopy indicated that the optical absorption values are larger than 104 cm− 1, Estimated band gap energy of CNTS absorber layers decrease from 1.64 to 1.5 eV with dip-coating cycle increased. The electrical conductivity of CNTS thin films increase from 0.19 to 4.16 (Ω cm)-1. These characteristics are suitable for solar cells applications.

scholarly journals Impact of Alkali Ions Codoping on Magnetic Properties of La0.9A0.1Mn0.9Co0.1O3 (A: Li, K, Na) Powders and Ceramics

2020 ◽  
Vol 10 (24) ◽  
pp. 8786
Author(s):  
Paweł Głuchowski ◽  
Ruslan Nikonkov ◽  
Robert Tomala ◽  
Wiesław Stręk ◽  
Tatsiana Shulha ◽  
...  
Keyword(s):  
High Pressure ◽  
Magnetic Properties ◽  
Exchange Interactions ◽  
Structural Disorder ◽  
Subsequent Increase ◽  
Cobalt Ions ◽  
X Ray ◽  
Alkali Ions ◽  
High Pressure Sintering ◽  
Combustion Technique

The aim of the work was to check how the introduction of alkali and cobalt ions into a manganese structure can affect the structural disorder and, in consequence, lead to the changes (improvements) of magnetic properties. The high-pressure sintering technique was applied to check if the external factor can modify the magnetization of manganites. Nanocrystalline La0.9A0.1Mn0.9Co0.1O3 (where A is Li, K, Na) powders were synthesized by the combustion technique. The respective powders were used for nanoceramics preparation by the high-pressure sintering technique. The structure and morphology of the compounds were studied by X-ray powder diffraction, scanning electron microscopy and energy-dispersive X-ray spectroscopy. Magnetization studies for all compounds were performed in order to check the changes induced by either codoping or the sintering pressure. It was found that the type of the dopant ion and sintering pressure produced significant changes to the magnetic properties of the studied compounds. Alkali ions lead to the stabilization of Co ions in the +2 oxidation state and the formation of positive exchange interactions Mn3+–Mn4+ and Co2+–Mn4+ and the subsequent increase in remanent magnetization. High sintering pressure leads to a decrease in grain size and reduction of long-range ferromagnetic order and lower magnetization.

Structure and Morphology Properties of Nanosized La0.75K0.05Ba0.05Sr0.15MnO3 Manganite

2020 ◽  
Vol 860 ◽  
pp. 106-111
Author(s):  
Dhawud Sabilur Razaq ◽  
Budhy Kurniawan ◽  
Ikhwan Nur Rahman ◽  
Dicky Rezky Munazat
Keyword(s):  
Bond Length ◽  
Crystallite Size ◽  
Sintering Temperature ◽  
Bond Angle ◽  
Sol Gel ◽  
Rhombohedral Structure ◽  
Phase Purity ◽  
X Ray ◽  
Structure And Morphology ◽  
Scanning Electron

Nanosized La0.75K0.05Ba0.05Sr0.15MnO3 manganite have been synthesized using sol-gel method. Afterwards, the samples were sintered at eight different temperature ranging from 650 to 1000 °C. Phase purity, crystal structure and the morphology of the sample have been examined using X-Ray Diffractometer (XRD) and Scanning Electron Microscope. It has been found that different higher sintering temperature greatly affect the phase purity and crystallite size of the sample. Regardless of the sintering temperature, all the samples crystallized in rhombohedral structure with R-3c space group. The crystallite size of the samples is found to increase from 41.59 nm up to 73.42 nm as the sintering temperature increases. Further analysis from XRD result shows that sintering temperature also affect the average Mn-O bond length and Mn-O-Mn bond angle of the sample. The average Mn-O bond length is found to increase while the average Mn-O-Mn bond angle tends to decrease as sintering temperature increases. SEM measurement shows that various grain size ranging from ~100 nm up to ~ 350 nm exists in all the sample regardless the sintering temperature.

Morphology Control of the Nano-MnO2 by Microwave Hydrothermal Synthesis

2012 ◽  
Vol 624 ◽  
pp. 47-50
Author(s):  
Shi Lei Zhang ◽  
Ben Niu ◽  
Enlei Qi ◽  
Lei Wang ◽  
Jie Qiang Wang
Keyword(s):  
Hydrothermal Synthesis ◽  
Energy Dispersive Spectrometer ◽  
Raw Material ◽  
X Ray Diffraction ◽  
Crystal Forms ◽  
X Ray ◽  
Microwave Assisted ◽  
Structure And Morphology ◽  
Microwave Hydrothermal ◽  
Scanning Electron

In this paper, KMnO4 was used as raw material, nano-MnO2 with different morphologies such as flowers globular, hollow tubular and rodlike were obtained by the microwave assisted hydrothermal synthesis under the acidic condition. The crystal structure and morphology of the resultant MnO2 were characterized by X-ray Diffraction (XRD) and Scanning Electron Microscope (SEM), respectively. The elements and content of samples were tested by Energy Dispersive Spectrometer (EDS). The influence of reaction temperature and holding time on crystal forms and morphologies of the MnO2 was analyzed.

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