arXiv subjects

M barek Amjoud

Publications and source records attributed to M barek Amjoud.

5 recordsLinked to original sources

arXiv2026

Enhancement in Magnetic and Magnetocaloric Properties of CoFe2O4 Nanofibers at Lower Temperatures

This research paper investigates new and first insights into the magnetic and magnetocaloric properties of one-dimensional (1D) cobalt ferrite CoFe2O4 (CFO) nanofibers elaborated by sol gel based electrospinning technique, particularly focusing on their behavior at low temperatures for specific applications. The calcined CFO nanofibers microstructural, structural, magnetic, and magnetocaloric properties were explored. The nanofibers (NFs) microstructure, with an average diameter of 210 nm, was examined by scanning and transmission electron microscopies (SEM, TEM). The X-ray diffraction (XRD) of the CFO nanofibers showed a pure cubic close-packed (c.c.p) spinel crystalline structure with the F d 3 -m space group. The Raman spectroscopic studies further confirm the cubic inverse spinel phase. The Magnetic properties were explored as a function of temperature, ranging from 10 to 300 K, a ferromagnetic behaviour was observed with the highest saturation magnetization of 75.87 emu g(-1) and a coercivity of 723 Oe at room temperature. The variation of the magnetic entropy was measured indirectly using the Maxwell approach with an increasing magnetic field. A maximum of Delta(S)=1.71 J K-1 was reached around 32 K. At 180 K, the associated adiabatic temperature change, Delta (Tmax), was 0.93 K, with a large RCP value of 7.58 J kg-1 was measured, which is reasonably high for the corresponding nanoparticles (NPs). This work may suggest that 1D CFO nanofibers offer a promising route for the production of nanostructured magnetic materials, potentially impacting various electronic and electromagnetic device applications at low temperatures.

cond-mat.mtrl-sci↗

arXiv2026

Rapid and Highly Efficient Synergistic Sonophotocatalytic Degradation of Methyl Orange with CuDoped LaFeO3 Perovskite Nanoparticles

The integration of sonocatalysis with photocatalysis offers a powerful strategy for advanced wastewater treatment by overcoming rapid charge carrier recombination in conventional photocatalytic systems. Although these processes are often treated separately due to their distinct mechanisms, their combination creates a highly efficient synergistic system. In this study, we investigate the sonophotocatalytic degradation of methyl orange (MO) using Cu-doped LaFeO3 perovskite nanoparticles. The Cu doped catalyst demonstrated excellent performance, achieving a degradation rate of 0.0455 min-1 and complete removal of MO within 120 minutes under combined ultrasonic and light irradiation. A strong synergistic effect was observed, with a synergy index of approximately 10, highlighting the enhanced interaction between sonocatalysis and photocatalysis. The catalyst also exhibited good stability and reusability, maintaining high efficiency over four consecutive cycles. Mechanistic studies using scavenger experiments revealed that hydroxyl radicals and photogenerated holes are the main reactive species responsible for degradation. A plausible reaction pathway is proposed based on these findings. Overall, Cu doped LaFeO3 shows superior sonophotocatalytic activity compared to the undoped material, demonstrating the potential of synergistic sonophotocatalytic processes for efficient pollutant removal.

cond-mat.mtrl-sci↗

arXiv2025

Current Advances in Magnetoelectric Composites with Various Interphase Connectivity Types

Magnetoelectric composites integrate the coupling between magnetic and piezoelectric materials to create new functionalities for potential technological applications. This coupling is typically achieved through the exchange of magnetic, electric, or elastic energy across the interfaces between the different constituent materials. Tailoring the strength of the magnetoelectric effect is primarily accomplished by selecting suitable materials for each constituent and by optimizing geometrical and microstructural designs. Various composite architectures, such as (0-3), (2-2), (1-3) and core-shell connectivities, have been studied to enhance magnetoelectric coupling and other required physical properties in composites. This review examines the latest advancements in magnetoelectric materials, focusing on the impact of different interphase connectivity types on their properties and performance. Before exploring magnetic-electric coupling, a brief overview of the historical background of multiferroic magnetoelectric composites is provided. Fundamental concepts underlying the magnetoelectric effect, piezoelectricity, and the magnetostrictive effect are explained, including their origins and examples of these materials' properties. So far, three types of magnetoelectric composite connectivities have been investigated experimentally: particulate composites (0-3), laminated and thin films (2-2), sticks embedded in matrix, core-shell particles, and coaxial fibers. An outlook on the prospects and scientific challenges in the field of multiferroic magnetoelectric composites is given at the end of this review.

cond-mat.mtrl-sci↗

arXiv2023

Room-temperature magnetoelectric effect in lead-free multiferroic $(1-x)$ Ba$_{0.95}$Ca$_{0.05}$Ti$_{0.89}$Sn$_{0.11}$O$_3$-$(x)$CoFe$_2$O$_4$ particulate composites

Multiferroic particulate composites $(1-x)$ Ba$_{0.95}$Ca$_{0.05}$Ti$_{0.89}$Sn$_{0.11}$O$_3$-$(x)$CoFe$_2$O$_4$ with ($x$ = 0.1, 0.2, 0.3, 0.4 and 0.5) have been prepared by mechanical mixing of the calcined and milled individual ferroic phases. X-ray diffraction and Raman spectroscopy analysis confirmed the formation of both perovskite Ba$_{0.95}$Ca$_{0.05}$Ti$_{0.89}$Sn$_{0.11}$O$_3$ (BCTSn) and spinel CoFe$_2$O$_4$ (CFO) phases without the presence of additional phases. The morphological properties of the composites were provided by using Field Emission Scanning Electron Microscopy. The BCTSn-CFO composites exhibit multiferroic behavior at room temperature, as evidenced by ferroelectric and ferromagnetic hysteresis loops. The magnetoelectric (ME) coupling was measured under a magnetic field up to 10 kOe and the maximum ME response found to be 0.1 mV /cm/ Oe for the composition 0.7 BCTSn-0.3 CFO exhibiting a high degree of pseudo-cubicity and large density.

cond-mat.mtrl-sci↗

arXiv2018

Very-low temperature synthesis of pure and crystalline lead-free Ba0.85Ca0.15Zr0.1Ti0.9O3 ceramic

The site-doping strategy of barium titanate (BaTiO3) is a promising way to develop new lead-free materials for energy with enhanced dielectric and piezoelectric properties. A novel strategy to elaborated pure and crystalline Ba0.85Ca0.15Zr0.1Ti0.9O3(BCZT) ferroelectric powders at low temperature is proposed. It is based on sol-gel method followed by a hydrothermal reaction. The effects of preparation temperature on structure, crystallinity, purity, morphology and particles size distribution of BCZT powders were studied. It was clearly shown that pure and crystalline BCZT could be obtained over 80°C. Furthermore, the BCZT particles exhibit a spherical shape whose mean size increases from 145 nm at 40°C to 160 nm at 80°C. The present study may provide a new strategy to design lead-free ferroelectric materials with enhanced structure and microstructure properties at very low temperature.

cond-mat.mtrl-sci↗