Search

The effect of using citrate-gel auto combustion method to substitute erbium rare-earth ion on magnetism cadmium composition of chemicals formula Cd0.2Mg0.8ErxFe2-xO4 (CMEF) (x = 0.000, 0.005, 0.010, 0.015, 0.020, and 0.025). Synthesized powder were sintered for 4 h at 600 °C after the crushed powders were calcined. These CMEF nanoferrites' structural and magnetic properties were investigated using P-XRD, E-DAX, FE-SEM, HR-TEM, FT-IR, and VSM investigations. Analysis has been done on the benefits of the crystallite size, phase, and various structural features of CMEF using P-XRD data. The assessed crystalline size is within the range of 20.43 nm and 24.30 nm, while the lattice constant ranges from 8.34 to 8.37 Å. photos obtained with the HR-TEM showed that the Er3+ doped Mg-Cd nanoferrites had particle sizes between 10.5 and 20.7 nm, while the FE-SEM photos showed grain sizes between 19.3 nm and 40.3 nm. With the help of elemental analysis (%) from EDAX, and the CMEF of elements that comprise the given chemical composition were thoroughly analysed without interfering substances. The spinel structure was confirmed by the presence of two stretching bonds between metal nitrates and function groups, as shown by the FT-IR spectra that were obeyed. VSM generates the characteristic hysteresis loops of the synthesised sample at 300 K temperature in the magnetic experiments. The findings showed that at 300 K, all of the MCEF nanoferrites exhibited ferromagnetic behaviour. Substantial magnetization was reached at 300 K for 20–18.48 emu/g). The Hc values were determined to lie between 107.46 and 129.53 Oe, while the squareness or remanent ratio values at 300 K varied. [ABSTRACT FROM AUTHOR]

Thermal energy and its storage systems play an extensive role in day-to-day life. They store renewable energy and are capable of recovering generated heat from different systems. Storage of thermal energy can be classified into three types: sensible, latent and sorption heat storages. Thermal heat storages use different types of materials based on their capacity of heat storage, stability of duration and thermal conductivity. Various phase change materials (PCMs) that are suitable for thermal storage are reported. Low conversion ability limits their effectiveness. We reviewed some of the traditional materials synthesized recently that are used for thermal energy storage (TES). Recently developed TES materials exhibit high thermal conductivity, reduced super cooling and multiple phase change temperatures. Nano-enhanced PCMs produced an increase in thermal conductivity up to 32% with a reduction in latent heat by 32%. At this juncture, MXenes with high performance and extraordinary properties (thermal, mechanical, etc.) are of special significance. MXenes displayed an increased thermal conductivity up to 16% and 94% efficiency. In view of their structure and adaptability to be used in thermal storage systems, an attempt was made to review their role also in thermal storage applications. It is observed that MXenes highly impact storage and efficiency. Apart from MXenes, various types of PCMs along with their thermal characteristics are presented. [ABSTRACT FROM AUTHOR]

In the present work, we have synthesized rare-earth ion modified Bi4−xRExTi2Fe0.7Co0.3O12−δ (RE = Dy, Sm, La) multiferroic compounds by the conventional solid-state route. Analysis of X-ray diffraction by Rietveld refinement confirmed the formation of a polycrystalline orthorhombic phase. The morphological features revealed a non-uniform, randomly oriented, plate-like grain structure. The peaks evident in the Raman spectra closely corresponded to those of orthorhombic Aurivillius phases. Dielectric studies and impedance measurements were carried out. Asymmetric complex impedance spectra suggested the relaxation of charge carriers belonging to the non-Debye type and controlled by a thermally activated process. Temperature-dependent AC conductivity data showed a change of slope in the vicinity of the phase transition temperature of both magnetic and electrical coupling natures. Based on the universal law and its exponent nature, one can suppose that the conduction process is governed by a small polaron hopping mechanism but significant distortion of TiO6 octahedral. The doping of the A-sites with rare-earth element ions and changes in the concentrations of Fe and Co ions located on the B-sites manifested themselves in saturated magnetic hysteresis loops, indicating competitive interactions between ferroelectric and canted antiferromagnetic spins. The magnetic order in the samples is attributed to pair-wise interactions between adjacent Fe3+–O–Fe3+, Co2+/3+–O–Co3+/2+, and Co2+/3+–O–Fe3+ ions or Dzyaloshinskii–Moriya interactions among magnetic ions in the adjacent sub-lattices. As a result, enhanced magnetoelectric coefficients of 42.4 mV/cm-Oe, 30.3 mV/cm-Oe, and 21.6 mV/cm-Oe for Bi4−xDyxTi2Fe0.7Co0.3O12−δ (DBTFC), Bi4−xLaxTi2Fe0.7Co0.3O12−δ (LBTFC), and Bi4−xSmxTi2Fe0.7Co0.3O12−δ (SBTFC), respectively, have been obtained at lower magnetic fields (<3 kOe). The strong coupling of the Aurivillius compounds observed in this study is beneficial to future multiferroic applications. [ABSTRACT FROM AUTHOR]

Energy storage and energy-storage devices have been a buzzword for long time as it is one of the essential needs in human life. These devices include mechanical systems, thermal systems, and batteries. These systems embedded with software can monitor the charging and discharging phenomena of energy. In this context, the role of rechargeable batteries needs to be reviewed. Even though novel types of rechargeable batteries are being continuously developed for storage of electricity, more attention and research towards supercapacitors is on the way. Huge number of researchers around the globe is involved in developing supercapacitors with improved performance making them more and more useful. The main aim is to improve their efficiency, energy density, operating voltage, miniaturization, optimization, economy, and environmental acceptance. For the last few years, lightweight and carbon-based novel wearable supercapacitors are developed. High durability, eco-friendliness, being non-volatile and electrostatic mechanism of supercapacitors make them advantageous than conventional batteries. In this regard, advances in microelectronics demand microsupercapacitors (MSCs). The selection of electrode in microsupercapacitor plays significant role in the fabrication. In this selection, MXenes as a family of 2D material play a vital role. Very high conductivity and high capacity of charge storage makes MXenes as one of the potential materials for electrodes in microsupercapacitors. This prompts us to review the role of MXenes in microsupercapacitors. This article reviews the recent advances of MXenes-based MSCs with emphasis on their fabrication techniques. [ABSTRACT FROM AUTHOR]

Liquid detection has been one of the buzzwords that refer to sensing of various liquids, which include water, chemicals, oils, etc. This detection gains more significance with the advent of metamaterials. Metamaterials are proved well suited in antenna designing, cloaking devices, solar cells, and sensors. Many papers reported metamaterial sensors, which can detect liquid chemicals, oils, etc. through shift in resonance frequency. Very few papers reported the applications of metamaterial sensors in water treatment. Water purification is one of the prime essentials for the existence of healthy humankind. It can be used to remove unwanted chemicals, contaminants and gases from water. The process of water purification can be done with various methods such as thermal, adsorption, distillation, desalination, reverse osmosis, etc. The main aim is to produce water required for specific purpose. In this context, role of metamaterials in water purification is of prime significance. Keeping this in view, an attempt is made to review the importance of metamaterial sensors in liquid detection along with water purification and its importance in comparison with earlier techniques already available. [ABSTRACT FROM AUTHOR]