AMAR Djemli
عمر جملي
amar.djemli@univ-msila.dz
0778435168
- Departement of Chemistry
- Faculty of Sciences
- Grade MAB
About Me
Location
Msila, Msila
Msila, ALGERIA
Code RFIDE- 1990-08-14 00:00:00
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AMAR Djemli birthday
- 2024-11-15
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2024-11-15
Kinetics of formation, microstructure, and properties of monolithic forsterite (Mg2SiO4) produced through solid-state reaction of nano-powders of MgO and SiO2
The synthesis of forsterite can be challenging because the initial oxides react slowly and undesirable compounds like enstatite (MgSiO3) can form instead of forsterite (Mg2SiO4). Although several methods have been developed to overcome these challenges, the synthesis of forsterite using the solid-state reaction of nanopowders has not been investigated. This study aims to explore the possibility of producing forsterite by reacting MgO and SiO2 nano-powder. The initial oxides were wet ball milled, dried, and reaction sintered. Spectroscopy and microscopy methods were used to analyze the formed phases and study the formation kinetics. The density, coefficient of thermal expansion (CTE), and hardness of sintered samples were measured using a densimeter, a dilatometer, and a hardness tester, respectively. The results demonstrated that it is possible to synthesize forsterite by solid state reaction of pure MgO and SiO2 nano-powders. The reaction between the two compounds begins at a temperature as low as 860 °C and leads to the formation of forsterite by a two-step formation mechanism. The first reaction involves the reaction of MgO and SiO2 to form enstatite, and the second one produces forsterite as a result of enstatite reacting further with MgO. The activation energy values ranged from 1028.89 to 1105.655 kJ/mol for the formation of forsterite, and from 456.316 to 488.08 kJ/mol for the formation of enstatite. Monolithic forsterite was completely formed at a low temperature of 1200 °C for a relatively short duration of 2 h. The sample sintered at 1400 °C for 2 h, had a density of 2.96 g/cm3, a Vickers hardness of 7.64 GPa, and a coefficient of thermal expansion of 10.24 × 10−6/K measured in the temperature range of 200–1300 °C.
Citation
KHADIDJA Laziri , AMAR Djemli , Foudil SAHNOUNE , Djaida Redaoui, Essebti Dhahri, Syed Fida Hassan, Nouari Saheb, , (2024-11-15), Kinetics of formation, microstructure, and properties of monolithic forsterite (Mg2SiO4) produced through solid-state reaction of nano-powders of MgO and SiO2, Ceramics International, Vol:50, Issue:22, pages:10, Elsevier
- 2023-10-27
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2023-10-27
Lanthanum Manganite LaMnO3 Crystallization Kinetics Prepared Through Sol-Gel Auto-Combustion Method
Lanthanum Manganite LaMnO3 Crystallization Kinetics Prepared Through Sol-Gel Auto-Combustion Method Abdelmadjid BOUSSENDEL1, Amar DJEMLI1, Foudil SAHNOUNE1, 2 1physics and materials chemistry laboratory, Department of Physics, University of M’sila, 28000 M’sila, Algeria 2Research Unit on Emerging Materials (RUEM), Ferhat Abbas of Setif 01, Setif 19000, Algeria Abstract This study focused on the synthesizing, phase transformation, and sintering behavior of Lanthanum manganite (LaMnO3), and the importance of such material due to its imbedded potential applications in various fields, including catalysis, energy storage, and solid oxide fuel cells. The sol-gel auto-combustion method was used in the preparation of the LaMnO3 sample, Sol-Gel method is known to it superior qualities such as high purity, homogeneous materials, and the ability to control particle size and morphology. The investigation of LaMnO3 sample phase transformation and sintering behavior was done in this study using several analytical techniques, thermogravimetry (TG), differential thermal analysis (DTA), and X-ray diffraction (DRX) analysis. In order to describe the energy barrier required for a particular process to occur such as a phase transformation or a chemical reaction, the activation energy (EA) for the phase transformation was calculated using three different methods: The Kissinger, Boswell, and Ozawa method. EA value was determined to be 173.8, 184, and 170 kJ/mol, respectively. which provides important information about the energy requirements for the phase transformation to occur for LaMnO3 materials, this information is extremely useful in the conditions of the process throughout designing and optimizing. The parameters that describe the reaction mechanism and the rate of the process are called kinetic parameters of Avrami n and m, which were calculated and found to be approximately 1.5. Overall, this study is essential because it provides insightful scope into the phase transformation and sintering behavior of LaMnO3. Keywords: differential thermal analysis, Phase Transformations, activation energy, crystallization kinetics Corresponding Author Email: abdelmadjid.boussendel@univ-msila.dz
Citation
Foudil SAHNOUNE , ABDELMADJID Boussendel , AMAR Djemli , ,(2023-10-27), Lanthanum Manganite LaMnO3 Crystallization Kinetics Prepared Through Sol-Gel Auto-Combustion Method,10th INTERNATIONAL CONFERENCE ON COMPUTATIONAL AND EXPERIMENTAL SCIENCE AND ENGINEERING (ICCESEN-2023) 27-30 October 2023, ANTALYA-TURKEY,ANTALYA-TURKEY
- 2023-10-27
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2023-10-27
Kinetics, Phase Transformations and Sintering of Mg-doped LaMnO3
Kinetics, Phase Transformations and Sintering of Mg-doped LaMnO3 Foudil SAHNOUNE1, Amar DJEMLI1, Abdelmadjid BOUSSENDEL1, Essebti Dhahri2, and Nouari Saheb3 1physics and materials chemistry laboratory, Department of Physics, University of M’sila, 28000 M’sila, Algeria 23Laboratoire de Physique Appliquée, Faculté des Sciences, Université de Sfax, B.P.1171, 3000 Sfax, Tunisia 3Dep. of Mechanical Engineering, King Fahd University of Petroleum and Minerals, Dhahran 31261, Saudi Arabia Abstract Lanthanum manganite (LaMnO3) is a complex oxide compound with various applications in wide fields, including solid oxide fuel cells, magnetic and electronic devices, catalysts, and multiferroics. Several available methods were used by researchers to prepare LaMnO3 such as solid-state synthesis, sol-gel method, hydrothermal synthesis, co-precipitation method, and assisted microwave synthesis, choosing a method depends on several factors, like desired particle size, morphology, purity, crystal structure of the LaMnO3, and the availability of resources and equipment. This study investigated the kinetics of LaMnO3 doped with magnesium ceramics synthesized using sol-gel method and starting materials as lanthanum nitrate (La (NO3)3*6H2O), manganese nitrate (Mn(NO3)2*6H2O), Magnesium nitrate (Mg(NO3)2*6H2O), and citric acid monohydrate (C6H8O7*H2O). In order to characterize the results, various techniques were used, including thermogravimetry (TG), differential thermal analysis (DTA), and X-ray powder diffraction (XRD). The activation energy (Ea) of La0.7Mg0.3MnO3 phase formation was measured by heat treating the sample up to 600 °C in various rates (0.3, 0.5, 0.7, and 1 °C/min) using differential thermal analysis (DTA). Using Kissinger, Boswell, and Ozawa methods Ea values were calculated and found to be 184, 189, and 185 kJ/mol, respectively. Both the growth morphology parameter n and the dimension of crystal growth m were determined to be approximately 1.5, suggesting that bulk nucleation with a constant number of nuclei was the dominant mechanism in La0.7Mg0.3MnO3 crystallization, which was followed by one-dimensional growth controlled by interface reaction. The tracking of the phase Transformations done by DTA at different temperatures (260, 400, 700, and 1100 °C) were analyzed using X-ray diffraction. Additionally, we analyzed the material's structural properties at different sintering temperatures (700, 800, 900, 1000, and 1100 °C) for 4 hours. Finally, we examined the changes in the crystal dimension of the material in consideration of both temperature and time. Keywords: Phase Transformations, activation energy, Sintering, crystallization kinetics Corresponding Author Email: foudil.sahnoune@univ-msila.dz
Citation
Foudil SAHNOUNE , AMAR Djemli , ABDELMADJID Boussendel , Essebti Dhahri, Nouari Saheb, ,(2023-10-27), Kinetics, Phase Transformations and Sintering of Mg-doped LaMnO3,10th INTERNATIONAL CONFERENCE ON COMPUTATIONAL AND EXPERIMENTAL SCIENCE AND ENGINEERING (ICCESEN-2023) 27-30 October 2023, ANTALYA-TURKEY,ANTALYA-TURKEY
- 2018-07-20
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2018-07-20
Heat treatment and kinetics of precipitation of β-Mg17Al12 phase in AZ91 alloy
This study investigated the effect of aging on the precipitation and kinetics of second-phase Mg17Al12 in AZ91 magnesium alloy (Mg-9 wt% Al-1 wt% Zn), using X-ray diffraction, microhardness measurements, and differential scanning calorimetric analysis (DSC). With the last instrument, the all samples were heated from room temperature to 400 °C, at heating rates of 10–30 °C/min. The results were supplemented by measuring the average of activation energies, using isothermal treatments by Johnson–Mehl–Avrami (JMA) methods and by non-isothermal treatments using Ozawa, Boswell, Kissinger, Mahadevan, Augis and Bennett methods, were around 67.18 and 62.02 kJ/mol. The frequency factor k0 calculated by the isothermal treatment is equal to 1.24 109 s−1. In non-isothermal treatment, the numerical factor m and the Avrami parameter n is estimated to be approximately equal to 3 and 2.79 respectively. This value corresponding that the bulk nucleation with a constant number of nuclei was dominant in three-dimensional (polyhedron) controlled by interface reaction
Citation
AMAR Djemli , Ameur Ouali , MohamedAmine GHEBOULI , Hocine BELHOUCHET , Fatmi messaoud, Tayab Chihi, , (2018-07-20), Heat treatment and kinetics of precipitation of β-Mg17Al12 phase in AZ91 alloy, Results in Physics, Vol:10, Issue:2018, pages:693-698, Elsevier