scholarly journals Effects of strain on La0.67-x Prx Ca0.33 MnO3, LaMn1-x Cox O3 and LaMn1-x Nix O3 magnetite samples

DYNA ◽  
2019 ◽  
Vol 86 (211) ◽  
pp. 278-287
Author(s):  
Javier Alberto Olarte Torres ◽  
María Cristina Cifuentes Arcila ◽  
Harvey Andrés Suárez Moreno
Keyword(s):  
Compressive Strength ◽  
Magnetic Susceptibility ◽  
Sol Gel ◽  
Morphological Characterization ◽  
Electric Resistivity ◽  
The Other ◽  
X Ray Diffraction ◽  
Metal Insulator ◽  
X Ray

This paper presents the results obtained from the synthesis and morphological characterization of different magnetite samples:  La0.67-x Prx Ca0.33 MnO3.LaMn1-x Cox O3 and LaMn1-x Nix O3 at 0.13 ≤ 𝑥𝑥 ≤ 0.67 produced by a solid-state reaction mechanism and 𝐿𝐿𝐿𝐿𝑀𝑀𝑀𝑀1−𝑥𝑥(𝐶𝐶𝐶𝐶/𝑁𝑁𝑁𝑁)𝑥𝑥𝑂𝑂3 at 0.0 ≤ 𝑥𝑥 ≤ 0.5 produced by the sol-gel method. These samples were characterized using X-ray diffraction spectroscopy and by measuring electric resistivity and magnetic susceptibility which were carried out as a function of temperature. Notably, the effects of strain and compressive strength on the lattices of magnetite samples were highly dependent on the concentration of 𝑃𝑃𝑟𝑟, 𝐶𝐶𝐶𝐶, and 𝑁𝑁𝑁𝑁. Moreover, the transition temperatures of metal-insulator and ferromagnetic-paramagnetic phases also largely depend on these strength effects, e.g., at higher concentrations of 𝑃𝑃𝑟𝑟, effects of increased strain strength were observed, relocating the shifts of ferromagnetic-paramagnetic transitions to lower temperatures. On the other hand, effects of increased compressive strength were observed at higher concentrations of 𝑁𝑁𝑁𝑁 and 𝐶𝐶𝐶𝐶, relocating the shifts of ferromagnetic-paramagnetic and metal-insulator transitions to higher temperatures.

Crossover from Metallic to Semiconducting in Pb2-xLnxRu2O7-δ (Ln = Eu, Sm) Compounds with Pyrochlore Structure

2009 ◽  
Vol 631-632 ◽  
pp. 483-488 ◽  
Author(s):  
Kato Masaki ◽  
Tetsuya Imamaura ◽  
Miho Fukatsu ◽  
Hirota Ken
Keyword(s):  
Magnetic Susceptibility ◽  
Pyrochlore Structure ◽  
Electric Resistivity ◽  
Strongly Correlated ◽  
X Ray Diffraction ◽  
Metal Insulator ◽  
X Ray ◽  
Resistivity Measurements ◽  
Spin Glass Transition ◽  
Semiconducting Behavior

We study the synthesis and physical properties of Pb2-xLnxRu2O7- (Ln = Sm, Eu) compounds with pyrochlore structure. The lead-lanthanoid pyrochlores Pb2-xLnxRu2O7- (Ln = Sm, Eu) have been successfully synthesized by the solid-state reaction. All samples were characterized by X-ray diffraction, magnetic susceptibility, and electrical resistivity measurements. Magnetic susceptibility measurements showed that the spin-glass transition temperature, TSG, decreases with Ln content x and goes to zero at x = 0.2 and 0.6 for Sm and Eu, respectively. From electric resistivity measurements, a crossover from metallic to semiconducting behavior was observed in the range of 0.2 ≤ x ≤ 0.4 and 0.4 ≤ x ≤ 0.8 in Pb2-xSmxRu2O7- and Pb2-xEuxRu2O7-, respectively. These boundaries between metallic and insulating phases mostly correspond to values of x with TSG = 0. These metal-insulator transitions can be caused by the strongly correlated couplings between the itinerant 4d electrons which are possibly attributed to the magnetic frustration.

scholarly journals Green synthesis and characterization of hexaferrite strontium-perovskite strontium photocatalyst nanocomposites

2020 ◽  
Vol 43 (1) ◽  
pp. 26-42 ◽  
Author(s):  
Zahra Hajian Karahroudi ◽  
Kambiz Hedayati ◽  
Mojtaba Goodarzi
Keyword(s):  
Magnetic Properties ◽  
Green Synthesis ◽  
Sol Gel ◽  
Synthesis Method ◽  
Combustion Method ◽  
Lemon Juice ◽  
X Ray Diffraction ◽  
X Ray ◽  
Auto Combustion

AbstractThis study presents a preparation of SrFe12O19– SrTiO3 nanocomposite synthesis via the green auto-combustion method. At first, SrFe12O19 nanoparticles were synthesized as a core and then, SrTiO3 nanoparticles were prepared as a shell for it to manufacture SrFe12O19–SrTiO3 nanocomposite. A novel sol-gel auto-combustion green synthesis method has been used with lemon juice as a capping agent. The prepared SrFe12O19–SrTiO3 nanocomposites were characterized by using several techniques to characterize their structural, morphological and magnetic properties. The crystal structures of the nanocomposite were investigated via X-ray diffraction (XRD). The morphology of SrFe12O19– SrTiO3 nanocomposite was studied by using a scanning electron microscope (SEM). The elemental composition of the materials was analyzed by an energy-dispersive X-ray (EDX). Magnetic properties and hysteresis loop of nanopowder were characterized via vibrating sample magnetometer (VSM) in the room temperature. Fourier transform infrared spectroscopy (FTIR) spectra of the samples showed the molecular bands of nanoparticles. Also, the photocatalytic behavior of nanocomposites has been checked by the degradation of azo dyes under irradiation of ultraviolet light.

The Ferroelectric and Electrical Properties of CaBi4Ti4O15 Thin Films Prepared by Sol-Gel Technology

2011 ◽  
Vol 239-242 ◽  
pp. 891-894 ◽  
Author(s):  
Tsung Fu Chien ◽  
Jen Hwan Tsai ◽  
Kai Huang Chen ◽  
Chien Min Cheng ◽  
Chia Lin Wu
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Sol Gel ◽  
Morphological Characterization ◽  
Experimental Result ◽  
X Ray Diffraction ◽  
Solution Deposition ◽  
Capacitance Voltage ◽  
Preferential Crystal Orientation

In this study, thin films of CaBi4Ti4O15with preferential crystal orientation were prepared by the chemical solution deposition (CSD) technique on a SiO2/Si substrate. The films consisted of a crystalline phase of bismuth-layer-structured dielectric. The as-deposited CaBi4Ti4O15thin films were crystallized in a conventional furnace annealing (RTA) under the temperature of 700 to 800°C for 1min. Structural and morphological characterization of the CBT thin films were investigated by X-ray diffraction (XRD) and field-emission scanning electron microscope (FE-SEM). The impedance analyzer HP4294A and HP4156C semiconductor parameters analyzer were used to measurement capacitance voltage (C-V) characteristics and leakage current density of electric field (J-E) characteristics by metal-ferroelectric-insulator- semiconductor (MFIS) structure. By the experimental result the CBT thin film in electrical field 20V, annealing temperature in 750°C the CBT thin film leaks the electric current is 1.88x10-7A/cm2and the memory window is 1.2V. In addition, we found the strongest (119) peak of as-deposited thin films as the annealed temperature of 750°C

scholarly journals Investigations of M3Al8O15:Eu3+,Dy3+ (M = Ba, Ca, Mg) phosphors

2016 ◽  
Vol 34 (2) ◽  
pp. 412-417
Author(s):  
Esra Öztürk
Keyword(s):  
Electron Microscopy ◽  
Solid State Reaction Method ◽  
Morphological Characterization ◽  
X Ray Diffraction ◽  
Reaction Method ◽  
X Ray ◽  
Three Samples ◽  
Scanning Electron ◽  
The Eu

AbstractIn this work, aluminate type phosphorescence materials were synthesized via the solid state reaction method and the photoluminescence (PL) properties, including excitation and emission bands, were investigated considering the effect of trace amounts of activator (Eu3+) and co-activator (Dy3+). The estimated thermal behavior of the samples at certain temperatures (> 1000 °C) during heat treatment was characterized by differential thermal analysis (DTA) and thermogravimetry (TG). The possible phase formation was characterized by X-ray diffraction (XRD). The morphological characterization of the samples was performed by scanning electron microscopy (SEM). The PL analysis of three samples showed maximum emission bands at around 610 nm, and additionally near 589 nm, 648 nm and 695 nm. The bands were attributed to typical transitions of the Eu3+ ions.

Morphological Characterization of Shape-Controlled TiO2 Anatase through XRPD Analysis

2016 ◽  
Vol 230 (9) ◽  
Author(s):  
Mauro Coduri ◽  
Michela Maisano ◽  
Maria Vittoria Dozzi ◽  
Elena Selli
Keyword(s):  
Morphological Characterization ◽  
Morphological Investigation ◽  
X Ray Diffraction ◽  
Preferential Growth ◽  
Rietveld Refinements ◽  
X Ray ◽  
Tio2 Anatase ◽  
Shape Controlled ◽  
Scherrer Equation

AbstractPreferential growth of anatase crystallites along different directions is known to deeply affect their photocatalytic properties, especially with respect to the exposure of the reactive {001} facets. Its extent can be easily quantified through simple geometric calculations, on the basis of crystal sizes extracted for specific directions by means of X-Ray Diffraction data analysis. Nevertheless, the actual results depend on the method employed for such a quantification. Here we report on a comparative morphological investigation, performed by employing the Scherrer equation and the line profile from Rietveld refinements, on shape-controlled anatase photocatalysts produced by employing HF as capping agent. Compared to the Rietveld-based method, the use of the Scherrer equation produces a systematic underestimation of crystallite dimensions, especially concerning the [100] direction, which in turn causes the percentage of exposed {001} crystal facets to be underestimated. Neglecting instrumental-related effects may further reduce the estimate.

Synthesis and characterization of MnO2nanowires

2017 ◽  
Vol 31 (02) ◽  
pp. 1750006 ◽  
Author(s):  
Mohammad Hossein Ghorbani ◽  
Abdol Mahmood Davarpanah
Keyword(s):  
Lithium Batteries ◽  
Manganese Oxides ◽  
Room Temperature ◽  
Annealing Temperature ◽  
Sol Gel ◽  
Average Crystallite Size ◽  
X Ray Diffraction ◽  
X Ray ◽  
Xrd Method

Manganese oxides are of more interest to researchers because of their ability as catalysts and lithium batteries. In this research, MnO2nanowires with diameter about 45 nm were synthesized by sol–gel method at room temperature (RT). Effect of increasing the annealing temperature from 400[Formula: see text]C to 600[Formula: see text]C on crystalline structure of nanostructure were studied and average crystallite size was estimated about 22 nm. X-ray Diffraction (XRD) method, Energy-Dispersive X-ray Diffraction (EDXD), Scanning Electron Microscopy (SEM) and Vibrating Sample Magnetometer (VSM) were used to characterize the nanowires of MnO2.

Synthesis and Characterization of Cadmium with Titanium Oxide (Cd-TiO2) Nanocomposite: Testing its Antibacterial Effect

2021 ◽  
Vol 12 (4) ◽  
pp. 2523-2529
Author(s):  
Daniel Sam N ◽  
Anish C I ◽  
Sabeena G ◽  
Rajaduraipandian S ◽  
Manobala ◽  
...  
Keyword(s):  
Sol Gel ◽  
Gram Negative Bacteria ◽  
X Ray Diffraction ◽  
Sem Images ◽  
Gram Negative ◽  
X Ray ◽  
Weight Percentage ◽  
Inhibition Concentration ◽  
Xrd Patterns

Sol gel methods were used for the study of the antimicrobial activity of Cd-TiO2 against gram-negative and positive bacteria. These Cd-TiO2 have been characterized by various optical and techniques. They have been exhibited by X-ray diffraction, scanning electron microscopy, ultraviolet spectroscopy, and infrared spectroscopy. The structures of the various XRD patterns indicate that the product has a structure. The particle size of Cd-TiO2 is 35nm. The SEM images confirm the spherical appearance of the sample. The energy X-ray spectra have been confirmed as well and then C, O, Ti, Cd, Pt element are present in Cd-TiO2. The weight percentage of Cadmium is 5.8%, Ti is 51.03%, C is 5.13% and O is 31.75% in Cd-TiO2. BET image shows that the major pore size distribution of Cd-TiO2 is ranged from 2.24 nm. The Cd-TiO2 that the antibacterial activity when tested against the pathogens only gram-negative bacteria such as Pseudomonas. The zone of minimum inhibition concentration was measured in a range of 20mm in 25μl and 30mm in 100μl.

scholarly journals Structural and morphological characterization of rare earth modified lead titanate

Cerâmica ◽  
2007 ◽  
Vol 53 (328) ◽  
pp. 422-447
Author(s):  
F. C. D. Lemos ◽  
D. M. A. Melo ◽  
P. S. de Lima ◽  
C. A. Paskocimas ◽  
E. Longo ◽  
...  
Keyword(s):  
Rare Earth ◽  
Lead Titanate ◽  
Pechini Method ◽  
Morphological Characterization ◽  
X Ray Diffraction ◽  
X Ray ◽  
Different Temperatures ◽  
Crystallite Sizes ◽  
Modifier Cation

Rare earth modified lead titanate powders Pb1-xRExTiO3 (REPT), x = 0.01, 0.05, 0.07 and RE = Yb, Y, were prepared by the Pechini method. The materials were calcined under flowing oxygen at different temperatures from 300 to 700 ºC. Nanostructured REPT were investigated using X-ray diffraction, scanning electron microscopy and surface area analysis (BET). The results suggest that the modifier cation incorporated into the system has notable influence in the microstructure and a notable decrease in the crystallite sizes.

scholarly journals Preparation and Characterization of Natural Zeolite Modified with Iron Nanoparticles

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Alvaro Ruíz-Baltazar ◽  
Rodrigo Esparza ◽  
Maykel Gonzalez ◽  
Gerardo Rosas ◽  
Ramiro Pérez
Keyword(s):  
Kinetic Models ◽  
Iron Nanoparticles ◽  
Morphological Characterization ◽  
Adsorption Kinetic ◽  
X Ray Diffraction ◽  
Modified Zeolite ◽  
X Ray ◽  
Transmission Electron ◽  
Zeolite Modification

This study is aimed at investigating the structural and morphological characterization of natural and modified zeolite obtained from the state of Oaxaca (Mexico). Iron nanoparticles were used for the zeolite modification. The iron nanoparticles were loaded on the zeolite surface by homogeneous nucleation. Adsorption kinetic models of pseudo first and second order were surveyed. The characterization of pristine and modified zeolite was performed by Fourier transform infrared (FTIR), transmission electron microscopy (TEM), and X-ray diffraction (XRD). From the results, three main phases were identified: clinoptilolite, mordenite, and feldspar. We could also determine the adsorption capacity of the zeolites by means of adsorption kinetic models.

scholarly journals Characterization of Slag Reprocessing Tailings-Based Geopolymers in Marine Environment

Minerals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 832 ◽  
Author(s):  
Jie Wu ◽  
Jing Li ◽  
Feng Rao ◽  
Wanzhong Yin
Keyword(s):  
Compressive Strength ◽  
Marine Environment ◽  
Copper Slag ◽  
X Ray Diffraction ◽  
Strength Measurement ◽  
X Ray ◽  
Sodium Aluminosilicate ◽  
Marine Concrete ◽  
Sodium Aluminosilicate Hydrate

In this study, copper slag reprocessing tailings (CSRT) were synthesized into geopolymers with 40%, 50% and 60% metakaolin. The evolution of compressive strength and microstructures of CSRT-based geopolymers in a marine environment was investigated. Except for compressive strength measurement, the characterizations of X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), nuclear magnetic resonance (NMR) and scanning electron microscopy (SEM) were included. It was found that marine conditions changed the Si/Al ratio in the sodium-aluminosilicate-hydrate (N-A-S-H) gel backbone, promoted the geopolymerization process, led to more Q4(3Al), Q4(2Al) and Q4(1Al) gel formation and a higher compressive strength of the geopolymers. This provided a basis for the preparation of CSRT-based geopolymers into marine concrete.

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