Double perovskite oxides are promising candidates for spintronic and magnetic applications because their magnetic properties can be effectively tailored through ionic substitution. In this work, the effects of non-magnetic Ag+ and magnetic rare-earth Sm3+ substitution at the Ba site of Ba2FeMoO6 were systematically compared for the first time at the same doping level (x = 0.05). Ba2−xAxFeMoO6 (A = Ag, Sm; x = 0.0 and 0.05) compounds were synthesized using the sol–gel method to investigate the influence of these dopants on the structural and magnetic properties of Ba2FeMoO6. The crystal structure, morphology, chemical states, and magnetic properties were characterized using X-ray diffraction with Rietveld refinement, FE-SEM, FTIR spectroscopy, XPS, and magnetic measurements. Structural analysis confirmed that all samples crystallized in a single-phase cubic structure with the Fm-3m space group. Although Ag+ and Sm3+ substitution did not change the crystal symmetry, slight modifications in the lattice parameters, unit-cell volume, and bond lengths were observed. FE-SEM images revealed an increase in porosity after doping, while FTIR spectra indicated changes in the vibrational modes associated with the MoO6 octahedra. XPS analysis confirmed the coexistence of Fe2+/Fe3+ and Mo5+/Mo6+ mixed valence states, which are essential for the double-exchange interaction. Magnetic measurements showed that both doped samples exhibited lower magnetization than the undoped compound. In contrast, Ag+ substitution reduced the magnetic transition temperature, whereas Sm3+ substitution increased it. These variations are attributed to dopant-induced structural distortions and changes in bond lengths, which modify the magnetic exchange interactions. The results provide new insights into the distinct roles of non-magnetic and magnetic dopants in tuning the structural and magnetic behavior of Ba2FeMoO6 double perovskites.

This research explores the magnetocaloric effect in the Ba1.95Ag0.05FeMoO6 double perovskite sample, which was synthesized via the sol-gel method. The critical exponents and the magnetocaloric effect of the sample were analyzed through both experimental and theoretical methods. These were determined using an iterative approach based on the Kouvel-Fisher analysis, modified Arrott plots, and the Widom scaling law. The transition from paramagnetic to ferromagnetic phases takes place at approximately 320 K. When a magnetic field of 3 T is applied, the maximum magnetic entropy change (-Delta S-M) close to the Curie temperature (TC) is about 0.690 J kg(-1) K-1, and the corresponding relative cooling power (RCP) at 3 T is approximately 48 J kg(-1). The magnetic entropy change was calculated using Landau theory and Maxwell's relation, demonstrating remarkable consistency.

In this study, the magnetocaloric effect of Ba2-xAxFeMoO6 (A = Sm, Ag and x = 0.0, 0.025) has been modeled. The samples exhibit a second-order transition from ferromagnetic (FM) to paramagnetic (PM) states at transition temperatures (TC) of approximately 310 K, 322 K, and 304 K for the Ba2FeMoO6 (BFMO), Ba1.975Ag0.025FeMoO6 (BAFMO), and Ba1.975Sm0.025FeMoO6 (BSFMO) samples, respectively. Investigation the magnetocaloric effect (MCE) in these samples involved simulating the change in magnetic entropy (− ΔSM). The critical exponents, β, γ, and δ were obtained using a numerical method grounded in Landau free energy within the mean-field approximation; the simulated outcomes strongly correlate with the experimental data.

The WS2 thin films were deposited on glass substrates using RF magnetron sputtering using a tungsten sulfide target to study the effect of WS2 layer thickness on the properties of the thin films. To analyze the morphological, structural, optical, electrical, and gas sensor characteristics of the thin films. The FESEM images indicated that samples have nanoparticles with 50, 150, and 250 nm thicknesses. The 50 and 250 nm and the sample of 150 nm have preferred orientations of (104) and (009), respectively. The 150 nm sample has a larger crystallite size than the other two samples and, as a result, has better crystallinity. Additionally, the Urbach energy calculation showed that the 150 nm sample had the lowest Urbach energy (74 meV), confirming better crystallinity and fewer crystal defects. The indirect band gap of the samples with increasing thickness is 1.89, 1.35, and 1.55 eV, respectively, which indicates that the 150 nm sample has the closest band gap value to the bulk state. Among the samples, the sample of 150 nm, which has better crystallinity and fewer crystal defects, has responded to the gas sensing of ethanol and ammonia in the self-powered mode. Measurements were performed at 500, 1500, and 2000 ppm and the recovery time for ethanol gas was 41.28 s.

In this study, silver nanoparticles were synthesized using aqueous extracts of Thymus leaves in three different volumes (1, 3, and 5 cc) as an eco-friendly and efficient alternative to conventional synthesis methods. Structural and optical characterizations were performed using X-ray diffraction, infrared spectroscopy, electron microscopy, and photoluminescence spectroscopy (under excitations at 380, 410, and 450 nm). The results confirmed the formation of face-centered cubic silver nanoparticles, with the sample prepared using 3 cc of extract showing optimal properties. This sample had a crystalline size of 37.2 nm, an average particle size of 196 nm, and exhibited 95.4 % degradation of methylene blue under UV-A light in 100 min. It also demonstrated the highest antibacterial activity, creating inhibition zones of 31 mm against Staphylococcus aureus and 27 mm against Escherichia coli. The study highlights the effectiveness of Thymus-mediated green synthesis for producing silver nanoparticles with strong antibacterial and photocatalytic performance, suitable for biomedical and environmental applications.

The WS2 thin films were deposited on glass substrates with RF magnetron sputtering using a WS2 target to study the effect of substrate temperature (25, 100, 200, and 300 °C) on their properties. In this study, we investigated the morphological, structural, and optical characteristics of the films. FESEM images show that all the samples consist of nanoparticles, with the exception of the film deposited at 200 °C, which uniquely exhibited a nanosheet morphology. The AFM spectrum of the samples determined that the sample with a substrate temperature of 200 °C had the highest roughness, which confirms the results obtained from the FESEM images of the samples. The XRD patterns of all the thin films showed the preferred orientation (104) related to the WS2 phase, and among the samples, the film deposited at 200 °C exhibited the largest crystallite size and the lowest strains. Also, no additional peak related to the oxide phase was observed in XRD and Raman spectra. The band gap of the 200 °C sample was lower than the other samples, and because it has a larger crystal size, this can be caused by quantum confinement. At 200 °C, the resistivity reached its highest value, accompanied by a significant decrease in carrier mobility and concentration, likely due to structural disorder and increased porosity in this sample.

The growing global energy demand and the pressing need for sustainable power solutions have intensified the search for innovative energy harvesting technologies. Triboelectric nanogenerators (TENGs) have emerged as promising candidates due to their ability to convert mechanical energy into electrical energy efficiently. This paper provides a comprehensive review of advanced materials and performance enhancement strategies for TENGs, emphasizing their critical role in addressing the current energy crisis. This review explores the foundational principles and operational modes of TENGs, including vertical contact-separation, lateral sliding, single-electrode, and freestanding triboelectric-layer modes. The paper highlights TENGs' unique attributes such as high efficiency at low frequencies, lightweight and flexible design, scalability, cost-effectiveness, and environmental friendliness, making them suitable for various applications. Key sections of this review focus on the advanced materials used in TENGs, including nanostructured surfaces and interfaces, hybrid and composite materials, and eco-friendly and biodegradable materials. Techniques such as nanoimprinting, etching, and nanomaterial coatings are discussed in detail, showcasing their impact on enhancing TENG performance. Furthermore, the review delves into performance enhancement strategies, covering multi-dimensional TENGs, optimization of contact electrification through surface modification, selection of triboelectric pairs, nano and microstructuring, and dynamic tuning mechanisms. By providing a thorough examination of these advanced materials and strategies, this paper underscores their importance in improving TENG efficiency and reliability, paving the way for sustainable energy solutions in the future.

Traditional water treatment methods face limitations in removing persistent organic pollutants due to slow degradation rates and incomplete mineralization. This study presents a novel metal-free heterostructured nanocomposite graphene quantum dots/g-C₃N₄ (GQCN) comprising graphene quantum dots (GQDs) and graphitic carbon nitride (g-CN) for enhanced photocatalytic degradation. GQDs were synthesized via pyrolysis, while g-CN was obtained through thermal treatment. Components were integrated through sonication-assisted mechanochemical approach to form efficient heterojunctions promoting charge separation. GQCN demonstrated superior photocatalytic performance for Rhodamine B (RhB) degradation under visible light compared to individual components. Optimal performance achieved 95.2% degradation efficiency within 120 min following pseudo-first-order kinetics with 35 mg/L catalyst loading. Maximum efficiency 98.2% was attained at pH 4.2 due to enhanced electrostatic interactions. The nanocomposite exhibited remarkable stability over five consecutive cycles. Comprehensive characterization using XRD, FT-IR, TEM, FESEM, EDX, UV-Vis DRS, fluorescence, DLS, zeta potential analysis, and PL spectroscopy confirmed successful heterostructure formation. Scavenger studies revealed hydroxyl radicals as predominant reactive species. This work introduces a practical strategy for fabricating metal-free photocatalysts with enhanced visible light activity, addressing scalability and environmental compatibility challenges, demonstrating significant potential for sustainable water treatment applications.

Biodegradable Mg alloys have considerable promise for use in bone-fixation devices. Nonetheless, their clinical application is limited due to the high degradation rate of Mg, leading to deterioration of the mechanical properties, and drastic change in pH of the surrounding cellular environment of the implant during the healing process. Recently, the use of Na-containing biocompatible coatings on the Mg surface has created an innovative approach to overcome the above problems. In this study, a newly developed sodium-containing zirconate hydrogel layer with an amorphous structure has been designed and prepared through modification of the Nb-containing (Zr-Nb) thin films sputtered directly on pure Mg using wet chemical conversion in aqueous NaOH solution. The results of the Grazing incidence angle X-ray diffraction (GI-XRD), X-ray photoelectron spectroscopy (XPS), and Energy dispersive Spectroscopy (EDS) analyses have certified the formation of the desired layer on top of the thin films, indicating that ion exchange and chemical conversion between the surface layers and solution has been limited to less than 200 nm from the (Zr-Nb) thin film thickness, but without the morphological changes in the thin film's surface layers. In terms of reducing Mg degradation, the NaOH-treated sample has been demonstrated to be superior, compared to the other samples tested, representing a decrease in the corrosion rate (CR) from 3.49 mm.y(-1) to 0.75 mm.y(-1), increase in the corrosion resistance (Rp) from 181.32 Omega cm(2) to 1911 Omega cm(2). This increase in corrosion resistance can be ascribed to the Na (+) ions released from the modified layers, resulting in a change in the pH and composition of the surrounding solution environment. Mechanically, the indentation and nano-scratch testing results have explained a slight increase in Young's modulus of the NaOH-treated thin film compared to the untreated one and maintained the thin film's scratch properties after and before the chemical surface treatment which can be attributed to the thickness (<200 nm) of the modified layer. Cell culture studies have demonstrated enhanced cell viability of MG-63 cells in the NaOH-modified surfaces compared to the un-modified ones. These results demonstrate that the zirconate sodium layers have created the protective effect, appropriate cellular response, and nano-mechanical properties illustrating their potential for use in biodegradable bone-fixation devices.

Anti-reflective coatings are essential for enhancing the efficiency of photovoltaic systems by minimizing surface reflections. In this study, TiO2 and SiO2 thin films were deposited on silicon substrates via sputtering and subsequently treated with an argon plasma jet for 5, 10, and 15 min. Optical emission spectroscopy confirmed the presence of active plasma species. Plasma treatment significantly reduced surface reflectance in the 450–750 nm range from 2.38 % to 0.59 %, 0.48 %, and 0.45 %, respectively consistent with Lumerical simulations. A concurrent decrease in refractive index was also observed. Structural analyses revealed the anatase phase prior to thermal treatment, evolving into a mixed anatase–rutile phase with enhanced crystallinity post-treatment. Moreover, plasma modification lowered surface roughness and improved coating uniformity, as confirmed by FE-SEM and AFM.

The escalating energy demands and the urgent need for sustainable power solutions have highlighted the potential of triboelectric nanogenerators (TENGs) as viable energy harvesting technologies. This paper continues the comprehensive review by focusing on the integration of TENGs with other technologies, their applications in wearable devices, and emerging future trends. This review introduces the integration of TENGs with various technologies, emphasizing hybrid energy harvesting systems, such as TENG-photovoltaic hybrids, TENGpiezoelectric generator systems, and TENG-TEG systems. The paper also explores the application of TENGs in smart systems and internet of things (IoT) applications, including self-powered sensors, IoT connectivity, wearable devices, environmental monitoring, smart homes, and industrial IoT. These integrations demonstrate TENGs' potential to enhance the efficiency and sustainability of modern technology. Significant attention is given to the advancements in wearable and flexible TENGs. This includes self-powered health monitoring, integration with smart clothing, biocompatible materials, and applications in rehabilitation and fitness tracking. The paper discusses the development of flexible and stretchable TENGs, highlighting innovations in stretchable polymers, serpentine interconnects, and encapsulation techniques, which expand the possibilities for wearable technology, soft robotics, and flexible electronics. Finally, the review addresses environmental and large-scale applications of TENGs, such as ocean wave and wind energy harvesting, and environmental monitoring and sensing systems. It also considers the future prospects and emerging trends, including the integration of TENGs with artificial intelligence and their application in next-generation technologies. By covering these areas, this paper underscores the transformative potential of TENGs in various domains, contributing to sustainable and efficient energy solutions for the future.

Certain materials (ceramics and polymers) are capable of converting mechanical energy into electrical energy via the piezoelectric effect. The piezoelectric effect is fundamentally associated with momentary electric dipoles that occur in solids. The external surface may be borne directly by molecular groups or excited in the crystal lattice by an asymmetric peripheral charge. Using molecular dynamics simulation, the current study examined the effect of atomic vacancies on the piezoelectric properties of barium titanate crystals. For this reason, the diffusion coefficient, ferroelectric hysteresis loop, piezoelectric hysteresis loop, and strain–polarization curve were all examined. Increasing atomic vacancy to 20

This study used molecular dynamics simulation to investigate how temperature changes the piezoelectric properties of crystal barium titanate in its tetragonal form. Consistent with the results, the oxygen diffusion coefficient in the simulated sample increased to 0.35 Å2/ns (expansion mode) and 0.56 Å2/ns (contraction mode) by increasing the temperature from 300 to 400 K. Moreover, the piezoelectric coefficient of samples decreased from 267.22 to 162.56 in an expansion mode and from 189.96 to 145.21 in a contraction mode by increasing temperature. On the other hand, increasing the temperature decreased saturation polarization (from 0.372 to 0.290 C/m2), coercivity field (from 0.259 to 0.155 MV/m), and residual polarization (from 0.154 to 0.084). This decrease may be due to approaching the critical temperature and changing the structure from tetragonal to cubic. Finally, the results show that the dielectric coefficients were found by raising the temperatures to 400 K (expansion mode) and getting 73, 70, 68, and 64. For the contraction mode, they were 70, 66, 55, and 63.

Double perovskite Ba2FeMoO6 (BFMO) substituted with monovalent Ag ions was synthesized using the sol-gel method, and its structure and magnetic properties were systematically studied. Rietveld refinement showed that the samples had a single phase with a cubic structure and an Fm-3m space group. With Ag substitution, the lattice parameter and unit cell of BFMO increased linearly, and the morphology of the samples was altered. X-ray photoelectron spectroscopy (XPS) examination showed mixed valence in the sample with x = 0.025 due to the Ag doping. The doped samples exhibited a decrease in magnetization, an increase in transition temperature, and anti-site (AS) defects. The AC magnetic susceptibility of the sample with x = 0.025 showed two peaks attributed to the two critical temperatures.

The impact of Sm3+ and Ag+ doping at the Ba2+ site on the structural, magnetic, and magnetocaloric properties of Ba2FeMoO6 (BFMO) double perovskite was compared. Samples were synthesized using the sol-gel method. Rietveld refinement patterns of samples Ba(2-x)A(x)FeMoO(6) (A=Sm, Ag, x = 0.0, 0.025) showed all samples had cubic structures with Fm-3 m space group and no impurity. The lattice parameters and unit cell of the Ba1.975Sm0.025FeMoO6 (BSFMO), and Ba1.975Ag0.025FeMoO6 (BAFMO) samples decreased compared to the parent sample. X-ray photoelectron spectroscopy confirmed that Fe and Mo ions were mixed valence for all samples. The results of magnetization versus temperature (M-T) showed an increase for BSFMO and a decrease for BAFMO samples under an external magnetic field of 0.05 T. The magnetic study indicated a decrease in the transition temperature for BSFMO (similar to 303 K) and an increase for BAFMO (similar to 321 K) to compare with the parent sample (similar to 310 K). The maximum value of magnetic entropy changes (Delta S-M(max)) of the BFMO, BSFMO, and BAFMO samples at H=3 T obtained 0.92 Jkg(-1)K(-1), 0.75 Jkg(-1)K(-1), and 0.39 Jkg(-1)K(-1), respectively, and the second-order magnetic phase occurred around the transition temperature. For BFMO, BSFMO, and BAFMO, the relative cooling power (RCP) is 34.48 J/kg, 32.25 J/kg, and 21.97 J/kg, respectively. The second-order magnetic phase transition occurred around the transition temperature for all samples using the energy criterion as well as the universal curve method. In addition, we used Widom's law to determine the critical exponent of the samples, which provides a new thermodynamic method to determine the magnetic phase transition. The results of the magnetocaloric effect indicate that although the maximum entropy changes and relative cooling decrease with doping Ag and Sm ions, they have a wide temperature range of magnetic entropy changes compared to the pristine sample, which can be candidates for magnetic cooling.

Double perovskite Ba2FeMoO6 (BFMO) and doped with Ag ions were synthesized via the sol-gel method. The structural and antibacterial properties and viability of the samples were systematically investigated. The results of the Rietveld refinement indicated that both samples exhibited a single phase with cubic structure and space group Fm-3m. The substitution of Ag ions led to an increase in the unit cell and lattice parameters of BFMO, resulting in a change in the sample's morphology. The direct band gap (∼2eV) was measured for samples by Diffuse Reflectance Spectroscopy (DRS). Antibacterial activity of the Ba2FeMoO6 and Ba1.95Ag0.05FeMoO6 samples was assessed on the Gram-positive bacteria (Staphylococcus aureus) and the Gram-negative bacteria (Escherichia coli) using the spread plate method. The results showed that the samples were effective against Staphylococcus aureus but not against Escherichia coli. The sample doped with Ag ions showed a higher antibacterial effect than the pristine sample. An MTT assay of the normal fibroblast cell line treated with an Ag-doped sample showed a higher percentage of viability.

This study investigated the piezoelectric properties of BaTiO3 ceramics with different sizes through molecular dynamics simulations. The results show that all samples reached thermal equilibrium at 300 K and equilibrium in potential energy within 10 ns, confirming effective equilibration. As the size of the ceramics increased, the mean square displacement and diffusion coefficients decreased from 0.217 and 0.0034 to 0.1934 & Aring;2 and 0.003 & Aring;2/ns, attributed to a more uniform microstructure with fewer defects, resulting in reduced ion mobility. Furthermore, saturation polarization, residual polarization, and coercive field values increased from 0.35, 0.1, and 0.175 to 0.42 C/m2, 0.16 C/m2, and 0.282 MV/m, respectively, with increasing sample size, highlighting enhanced polarization responses due to a greater volume of ferroelectric material. Larger barium titanate (BaTiO3) crystals can have better polarization due to more domains aligning, but they may not deform as much (lower strain) because the walls among those domains can't move freely. While improved domain alignment contributed to higher polarization, the increased stress can restrict the mobility of the domain walls. These findings provided valuable insights into the size-dependent behavior of BaTiO3 ceramics, essential for optimizing their applications in electronic devices and sensors. The study underscored the importance of understanding microstructural effects on material properties for future advancements in ferroelectric technology.

This study investigates the critical behavior analysis and predicting magnetocaloric properties of La0.6-xGdxSr0.4MnO3 manganites, focusing on the impact of varying gadolinium (Gd) doping levels (x = 0, 0.0125, 0.05, and 0.10). Using modified Arrott plots (MAPs) and the Kouvel–Fisher method, the critical exponents γ and β were determined, yielding values that indicate how Gd content influences magnetic phase transitions. Additionally, the magnetocaloric effect (MCE) was analyzed to assess the magnetic entropy change -ΔS_M(T) and the Temperature-Averaged Entropy Change (TEC) across different magnetic field changes. The results show that increasing Gd doping enhances the magnetocaloric response, suggesting potential applications in magnetic refrigeration. Overall, the study provides insights into optimizing these manganites for applications in high-temperature sensors, spintronics, and magnetic cooling.

Ba2FeMoO6 samples were prepared using the sol-gel method without and using Cetyltrimethylammonium bromide (CTAB) to study their photocatalytic properties. The structural and morphological properties of the samples were characterized systematically. The Rietveld refinement described a cubic structure with space group Fm-3m and a single phase with no detectable impurity for either. FESEM images showed that the sample's morphology changed significantly with the addition of the CTAB. The BET analysis of the sample containing CTAB (BFMOC) showed that the special surface area of the pores increased ten times compared to parent sample and its pore size decreased. The UV-Vis spectrum of the BFMOC sample showed two absorption peaks at 223 nm and 705 nm in the ultraviolet and visible regions, respectively. Diffuse reflectance spectroscopy (DRS) spectra of the samples showed direct band gaps (∼2eV) for both. Photocatalytic and absorbent properties were observed in both samples. The photocatalytic properties of the samples revealed that they effectively degraded the dye triphenylmethane MG. By adding CTAB, the Curie temperature of the BFMO sample increased from 304 K to 310 K, while saturation magnetization decreased from ∼1.43 μB/f.u to ∼0.89 μB/f.u. The low coercive field value indicates that the both samples possess soft magnetic and ferromagnetic properties.

Double perovskite Ba 2 FeMoO 6 (BFMO) substituted with monovalent Ag ions was synthesized using the sol-gel method, and its structure and magnetic properties were systematically studied. Rietveld refinement showed that the samples had a single phase with a cubic structure and an Fm -3m space group. With Ag substitution, the lattice parameter and unit cell of BFMO increased linearly, and the morphology of the samples was altered. X-ray photoelectron spectroscopy (XPS) examination showed mixed valence in the sample with x = 0.025 due to the Ag doping. The doped samples exhibited a decrease in magnetization, an increase in transition temperature, and anti -site (AS) defects. The AC magnetic susceptibility of the sample with x = 0.025 showed two peaks attributed to the two critical temperatures.