35 documents found, page 1 of 4
Study of physical properties of the Li0.5MgFe1.5O3.5 ferrite nanoparticles
Jeidd, Abddaim; Amghar, Mohamed; Mabrouki, A; Benali, A.; Trabelsi, A; Dhahri, E; Khirouni, K; Costa, B. F. O.In the present research study, the structural, optical, magnetic, electrical and dielectrical properties of the spinel ferrite Li0.5MgFe1.5O3.5, synthesized using a sol-gel auto-combustion method were studied. X-ray diffraction, Fourier transform infrared spectroscopy (FTIR), and Raman spectroscopy revealed that this sample crystallizes in a cubic spinel structure with space group Fd3̄m. Moreover, the optical i...
Summerfield scaling model and electrical conductivity study for understanding t...
Elhamdi, I.; Mselmi, F.; Souissi, H.; Kammoun, S.; Dhahri, E.; Sanguino, P.; Costa, B. F. O.Solid-state and sol-gel procedures were used to prepare ZnAl1.95Cr0.05O4 nanocrystal spinels. From the results obtained by X-ray diffraction (XRD) and transmission electron microscopy (TEM), it can be concluded that the samples prepared by sol-gel synthesis are better crystallized than the ones resulting from the solid-state method. Studies by spectroscopy of impedance were done in function of frequency (40-107...
Study of the structural, electrical, dielectric properties and transport mechan...
El Heda, I.; Dhahri, R.; Massoudi, J.; Dhahri, E.; Bahri, F.; Khirouni, K.; Costa, B. F. O.Cu0.5Fe2.5O4 nanoparticles were synthesized by the self-combustion method whose XRD and FTIR analyzes confirm the formation of the desired spinel phase. The thermal evolution of conduction shows a semiconductor behaviour explained by a polaronic transport mechanism governed by the Non-overlapping Small Polaron Tunnelling (NSPT) model. DC conductivity and hopping frequency are positively correlated. The scaling ...
Study of the effect of the substitution of Fe by Ti on the microstructure and t...
Dhahri, R.; Valente, M. A.; Graça, P.; Costa, B. F. O.La0.67Ca0.2Ba0.13Fe1-xTixO3 samples (x = 0 and 0.03) were synthesized by the auto-combustion method. Analysis of XRD diffractograms revealed that these compounds crystallize in the cubic system with the space group Pm3̄m. The dielectric properties have been studied in the 102-106 frequency range and the 120-280 K temperature range. Analysis of AC conductivity shows that the conduction mechanisms are of polaroni...
Electronic, electrical and thermoelectric properties of Ba0.95Ca0.05Ti0.95Y0.05...
Saidi, A.; Mabrouki, A.; Dhahri, R.; Dhahri, E.; Khirouni, K.; Costa, B. F. O.This article explores the impact of co-doping BaTiO3 ceramics with Ca2+ and Y3+ using solid-state reactions to improve its dielectric constant and decrease losses. The oxide BCTYO (Ba0.95Ca0.05Ti0.95Y0.05O2.975) exhibits a tetragonal crystal structure, characterized by a space group of P4mm. By examining the behavior of the doped BaTiO3 sample and performing simulations, researchers can better understand the un...
Investigation of temperature and frequency dependence of the dielectric propert...
Bougoffa, Amira; Benali, E. M.; Benali, A.; Bejar, M.; Dhahri, E.; Graça, M. P. F.; Valente, M. A.; Otero-Irurueta, G.; Costa, B. F. O.In this work we synthesized the multifunctional (La0.8Ca0.2)0.4Bi0.6FeO3 material using a sol-gel process. Structural and morphologic investigations reveal a Pnma perovskite structure at room temperature with spherical and polygonal nanoparticles. A detailed study of the temperature dependence of the dielectric and electrical properties of the studied material proves a typical FE-PE transition with a colossal v...
Synthesis and study of the structural and dielectric properties of La0.67Ca0.2B...
Dhahri, A.; Zaouali, A.; Benali, A.; Abdelmoulla, N.; Massoudi, J.; Nouri, K.; Bessais, L.; Graça, M. P. F.; Valente, M. A.; Costa, B. F. O.The La0.67Ca0.2Ba0.13Fe1-xMnxO3 perovskite compounds with different manganese concentrations (x = 0.0, 0.03, 0.06) were synthesized by the autocombustion method and annealed at 700 C. The X-ray diffraction (XRD) data indicated that all obtained compounds crystallize in the cubic structure with the Pm3m space group. The increase in the substitution rate has been found to lead to the decrease in the crystallite s...
Electrical conductivity and dielectric properties of Sr doped M-type barium hex...
Marouani, Y.; Massoudi, J.; Noumi, M.; Benali, A.; Dhahri, E.; Sanguino, P.; Graça, M. P. F.; Valente, M. A.; Costa, B. F. O.The Raman results showed that the intensity of the resonance band remains unchanged in Ba1 xSrxFe12O19 compared to the undoped compound (x ¼ 0) indicating that the polarizability did not change during the vibrations. The particle sizes, observed by TEM, are reduced from 228 nm to 176 nm with doping. Electrical conductance measurements show that all samples present semiconductor-like behaviors. The Maxwell–Wagne...
Structural, morphological, Raman, dielectric and electrical properties of La1-2...
Benali, E. M.; Benali, A.; Bejar, M.; Dhahri, E.; Graca, M. P. F.; Valente, M. A.; Costa, B. F. O.La1-2x Ba x Bi x FeO3 (0.00 ≤ x ≤ 0.20) nanoparticles were prepared by the auto-combustion method using glycine as a combustion fuel. X-ray diffractometry (XRD) measurements confirmed the orthorhombic structure of the synthesized compounds with the Pnma space group as a principal majority phase and showed the presence of a very minor secondary phase when x > 0.1. The nanosize criterion of the prepared compounds...
Study of the influence of 2.5% Mg2+ insertion in the B-site of La0.8Ca0.1Pb0.1F...
Issaoui, H.; Benali, A.; Issaoui, F.; Dhahri, E.; Costa, B. F. O.; Graca, M. P. F.; Valente, M. A.; Bouazizi, Mohamed LamjedThis work involves the synthesis and study of physical properties of the La0.8Ca0.1Pb0.1Fe0.975Mg0.025O3 compound, which has been characterized by various experimental techniques, such as X-ray diffraction, SEM and complex impedance spectroscopy. The structural study showed that the La0.8Ca0.1Pb0.1Fe0.975Mg0.025O3 compound crystallized in the orthorhombic structure with the Pnma space group. The particle size a...