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Abstract This research paper delves into the enhancement of wastewater treatment through the design and synthesis of advanced photocatalytic materials, focusing on the effects of sodium (Na) substitution in Ca1‐xNaxTa0.5Ti0.5O3 perovskites. By employing various analytical techniques such as X‐ray diffraction, Field Emission Scanning Electron Microscopy, Transmission Electron Microscopy and UV‐vis spectroscopy, the study examines the transition of these perovskites from tetragonal to orthorhombic structures and observes a reduction in Ca content with Na substitution, which also favors the cubic phase formation and inhibits secondary phases. Significantly, magnetic property analysis uncovers an unexpected ferromagnetic ordering in these perovskites, including compositions traditionally viewed as non‐magnetic. The photocatalytic tests reveal a significant improvement in degrading Rhodamine B dye under visible light, particularly in samples with higher Na levels, attributed to enhanced light absorption and efficient electron processes. The study highlights the optimal Na substitution level for peak photocatalytic performance, offering valuable insights into the complex interplay between structural, magnetic, and photocatalytic properties of these perovskites, and their potential in various applications, thereby contributing to the advancement of wastewater treatment technologies.

Despite the advantages of electric field efficiency and miniaturization, the limited operating temperature range and mediocre cooling efficiency of electrocaloric thin films represent the key obstacles to their practical applications in cooling advanced electronics. In this review, we discussed the current efforts and challenges facing the development of high-performance electrocaloric thin films and explored universal approaches along with their physical mechanisms for optimizing the electrocaloric response in thin films. We first emphasize the significance of the indirect method for determining the electrocaloric effect (ECE) in thin films and restate the conditions for the application of Maxwell’s equations. Particularly, we flag a couple of common artifacts of the electrocaloric results induced by the indirect method in recent attempts at the optimization of the ECE. We then cover chemical modification, interface engineering, and strain engineering as effective routes to improve the adiabatic temperature change (ΔT), reduce the driving electric field (E), and widen the operating temperature range (Tspan). At last, we propose that slush relaxors can be exploited as the base system for simultaneously achieving large ΔT, broad Tspan, and low E. Furthermore, we also discuss that the employment of high-entropy oxide perovskites is a feasible approach for greatly raising the dipolar entropy change under low electric fields. At last, we stress the significance and pressing need to measure the EC parameters of thin films with reliable direct methods. We hope that the high-performance electrocaloric thin films and the design rationale discussed in this review could inspire more facile and novel methods to achieve a better electrocaloric response.

This research paper delves into the enhancement of wastewater treatment through the design and synthesis of advanced photocatalytic materials, focusing on the effects of sodium (Na) substitution in Ca1‐xNaxTa0.5Ti0.5O3 perovskites. By employing various analytical techniques such as X‐ray diffraction, Field Emission Scanning Electron Microscopy, Transmission Electron Microscopy and UV‐vis spectroscopy, the study examines the transition of these perovskites from tetragonal to orthorhombic structures and observes a reduction in Ca content with Na substitution, which also favors the cubic phase formation and inhibits secondary phases. Significantly, magnetic property analysis uncovers an unexpected ferromagnetic ordering in these perovskites, including compositions traditionally viewed as non‐magnetic. The photocatalytic tests reveal a significant improvement in degrading Rhodamine B dye under visible light, particularly in samples with higher Na levels, attributed to enhanced light absorption and efficient electron processes. The study highlights the optimal Na substitution level for peak photocatalytic performance, offering valuable insights into the complex interplay between structural, magnetic, and photocatalytic properties of these perovskites, and their potential in various applications, thereby contributing to the advancement of wastewater treatment technologies. [ABSTRACT FROM AUTHOR]

ZnFe2O4 (ZFO) NPs (nanoparticles), Co0.5Ni0.5Ga0.01Gd0.01Fe1.98O4 (CNGaGdFO) NPs and hard-soft spinel ferrite (H/S) (CNGaGdFO)x/(ZFO)y (x:y = 1:1, 1:2, 1:3, 2:1, 3:1 and 4:1) NCs (nanocomposites) were synthesized via a one-pot sol–gel auto combustion route. X-ray powder diffraction (XRD) analyses confirmed the purity of ZFO NPs, CNGaGdFO NPs and H/S (H/S) (CNGaGdFO)x/(ZFO)y (x:y = 1:1, 1:2, 1:3, 2:1, 3:1 and 4:1) (absence of any second phase). The crystallite size of NCs was between 39 and 52 nm. The cubic morphology was observed for ZFO NPs, CNGaGdFO NPs and all H/S NCs by the help of scanning electron microscopy (SEM) and transmission electron microscopy (TEM) analyses. Energy dispersive X-Ray analysis (EDX) also confirmed the chemical formula of all the NC samples. Electrical and dielectric properties of ZFO NPs, CNGaGdFO NPs and H/S NCs were explored with an impedance analyzer with f ≤ 3.0 MHz, where f stands for frequency, and within the temperature range between 20 and 120 °C. Electric and dielectric parameters such as AC conductivity as well as DC conductivity, activation energy, dielectric constant, dielectric loss in addition to the dissipation parameter relevant to the electrical energy due to different physical processes were measured for each of the given compositional ratios. The AC conductivity was found to follow the frequency-dependent power law in general, being mainly reliant on the compositional ratios and the measured temperatures especially at lower frequencies. This study has shown that CoNiGaGdFeO-ZnFe2O4 H/S NCs carry out conduction mechanisms, which can be predominantly credited to grain–grain boundaries for various compositional ratios. The dielectric constant of (CNGaGdFO)x/(ZFO)y (x:y = 1:1, 1:2, 1:3, 2:1, 3:1 and 4:1) H/S NCs indicates common dielectric behaviours with frequency, largely dependent on compositional rates of the hard to soft spinel ferrites. It is observed that hard ferrite is dominant in the formation of the semicircles, and the diameter of the semicircles shows a drop as the temperature rises, suggesting a temperature-dependent relaxation mechanism. Consequently, the observed variation of the studied dielectric parameters with frequency can be explained by the conduction mechanism in most composition ratios of hard to soft spinel ferrites, which can be explained by a phenomenological method with Koop's model.

As a result of an increase in the availability of resources that were not harmful to the environment, solar energy applications shot to popularity. Photovoltaic cells power systems that necessitate DC-DC converters because of their low voltage output. This investigation uses photovoltaic cells (PV) to power a high-voltage gain design with just one switch and no transformer. The proposed circuit utilizes a single regulated switch, which contributes to a reduction in switching losses. It requires fundamental pulse regulation. The network used a switched capacitor cell and an LC passive filter to provide an accurate step-up voltage. We can obtain the equation for the step-up voltage gain from the steady-state continuous conduction mode. The equations used for the theoretical design of converters include energy. To show that the topology is comparable with other modern converters that have been published, a comparison was made between it and other converters. In order to validate the converter's effectiveness, simulations built in MATLAB and Simulink are used. [ABSTRACT FROM AUTHOR]

Lanthanide-based manganite perovskites due to their possible integration both in conventional Si-based electronics, and in innovative full-oxide electronics, have led to a massive resurgence of interest. The properties and applicability of these perovskites can be tailored with the interplay of foreign ion substation, and thus lot of efforts have been made by the researchers by using various types of compound combinations. In this work, a systematic study of Ba-substituted lanthanide of a chemical formula La 0. 5 7 Sm 0. 1 Sr 0. 3 3 − x Ba x MnO3 (where, x = 0. 0 , 0.05, 0.1, 0.20 and 0.33) was done and the manganites were synthesized by sol–gel auto-combustion method. The structural and magnetic properties were investigated by thermogravimetric/differential thermal analysis, which was also carried out to investigate the thermal stability of the prepared samples. X-ray diffraction (XRD) patterns, transmission electron microscopy (TEM), scanning electron microscopy (SEM) etc. were employed to investigate the crystallographic structure. XRD patterns and selected area electron diffraction patterns revealed the formation of single-phase La 0. 5 7 Sm 0. 1 Sr 0. 3 3 − x Ba x MnO3 perovskite materials without any signature of secondary phases. Elemental composition of the synthesized samples was investigated by the energy dispersive analysis of X-ray analysis, which confirmed the expected stoichiometry of the prepared samples. TEM and SEM observations revealed the nano-crystalline nature of the prepared samples, where particle size obtained from TEM ranges from 40 nm to 70 nm. It has been found that structural and magnetic properties of the parent La 0. 5 7 Sm 0. 1 Sr 0. 3 3 MnO3 system were greatly affected by the Ba substitution. In this study, Ba-substituted La–Sm–Sr–Mn manganites were synthesized using the sol–gel auto-combustion method. This technique was employed to meticulously craft the nanoparticles, highlighting its effectiveness in creating nanostructures. The primary focus of the research was on magnetization behavior, with initial findings indicating a notable increase in magnetization upon Ba substitution, reaching its maximum at x = 0.05. [ABSTRACT FROM AUTHOR]

A mixture of soft–hard (S–H) ferrites with the general chemical formula (1‐x) Ni0.5Cu0.25Zn0.25Fe2O4 (NCZFO) + (x) SrFe11Y1O19 (SFYO) is developed via sol‐gel auto‐combustion and their physical mixing. X‐ray diffraction (XRD), Fourier transform infrared spectroscopy, field emission scanning electron microscopy (SEM) coupled with energy dispersive X‐ray spectroscopy, high‐resolution transmission electron microscopy (HRTEM), vibrating sample magnetometry (VSM) and two‐probe technique are used to examine the resultant materials. Rietveld refinement of XRD data confirms the co‐existence of both soft and hard phases in the composites. The HRTEM and FESEM results confirm the nanocrystalline nature of the synthesized particles. Williamson‐Hall method is employed to reveal the strain nature in soft and hard phases. VSM analysis shows considerable changes in the magnetic characteristics for the different composition of NCZFO and SFYO. The exchange‐spring mechanism is discussed in the manuscript. [ABSTRACT FROM AUTHOR]

Abstract We have fabricated a high quality magnetic Ni0.5Zn0.5Fe2O4 ferrite powder/polymer composite sheet consisting of common and environmentally friendly elements only. The sheet was then tested for its dynamic permeability by irradiating with electromagnetic waves with frequencies up to 50 GHz. Two different originally developed methods were used for the high-frequency permeability measurements, a short-circuited microstrip line method and a microstrip line-probe method. It is challenging to measure the dynamic permeability of magnetic thin films/sheets beyond 10 GHz because of the low response signal from these materials. However, the two methods produced essentially equivalent results. In the frequency dependent permeability profile, the maximum position of the profile, $$\mu ^{\prime \prime }_{max}$$ μ max ″ , shifted towards higher frequencies upon increasing an applied (strong) static external magnetic field, $$H_{dc}$$ H dc . A linear relationship between $$\mu^ {\prime \prime }_{max}$$ μ max ″ and $$H_{dc}$$ H dc for the entire range of $$H_{dc}$$ H dc was observed even at small $$H_{dc}$$ H dc . In general, the spinel-structured Ni-based ferrites exhibit low magnetic anisotropy, but the present sample showed a uniaxial-anisotropic behavior in the parallel direction of the sheet. Our Ni0.5Zn0.5Fe2O4 powder/polymer composite sheet thus exhibits high performance at GHz frequencies, and should be applicable e.g. as an anisotropic electromagnetic wave-interference material.