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Considering the multifunctional performance, the (Ba0.7Sr0.3)0.98Ca0.02Ti1−xCoxO3 (x = 0.00–0.2) ceramics are successfully synthesized using the traditional solid‐phase reaction method. The effect of cobalt doping on the samples' structural, morphological, magnetic, electrical, and optical characteristics is elucidated. Raman spectroscopy and X‐ray diffraction data confirm the dopants' integration into the cubic perovskite microstructure. At room temperature, the magnetization–magnetic field intensity hysteresis loops from vibrating sample magnetometer reveal the samples' ferromagnetic character, with a maximum magnetization of 0.091 emu g−1 achieved for x = 15%. The real part of the initial permeability demonstrates that the replacement of Co2+ causes a shift in resonance toward higher frequencies above 85 MHz, indicating the potential of the synthesized ceramics for high‐frequency magnetic applications. The variation in dielectric characteristics from 100 Hz to 10 MHz is explained using electron hopping on octahedral sites and Maxwell–Wagner's model. The increase of AC conductivity in the high‐frequency region is consistent with the strengthening of the grain effect on the conduction mechanism, which supports the small‐range polaron‐hopping theory. The complex electric modulus's peak (M′′) shifts toward a higher‐frequency region with cobalt content, suggesting a reduction in the relaxation rate. The optical bandgap is observed to decrease from 3.08 to 2.96 eV with cobalt content. [ABSTRACT FROM AUTHOR]

Catalytic activity of spinel ferrite in breaking down toxic dye materials are promising due to their uniqueness. In this study, aluminum‐doped copper zinc ferrite, Cu0.4Zn0.6‐xAlxFe2O4 (x = 0.0, 0.2, 0.4, 0.6), a catalyst for toxic dye degradation is synthesized through chemical co‐precipitation route. The formation of the spinel ferrite catalyst is initially confirmed by Fourier transform infrared spectra, which shows the frequency of metal‐oxygen bond vibration at 539 and 427 cm−1 attributed to the tetrahedral and octahedral sites respectively. Higher intensity sharp peak of X‐ray diffraction for (311) plane is the evidence for the phase purity and the formation of spinel ferrite. The crystallite size is found to decrease with the increase of Al3+ ion. The surface structure of the obtained particles is investigated using a scanning electron microscope. Analyses of the material's magnetic characteristics using a vibrating sample magnetometer (VSM) revealed that it is, in fact, a soft magnet, as evidenced by the loop of its hysteresis, which is narrow. The catalytic degradation of methylene blue dye under the mechanism of the photo‐Fenton process is studied with the obtained spinel ferrites and the result is found to be as high as 96.5%. The process follows pseudo‐second order kinetics and the Langmuir isotherm. [ABSTRACT FROM AUTHOR]

In this work, multiferroic composites of (1−x) Ba0.77Ca0.23TiO3 + x Ni0.6Zn0.25La0.15Fe2O4 (x = 0.0, 0.1, 0.2, 0.3, 0.5, 0.7, 0.9 and 1.0) have been synthesized using solid-state reaction method and their different properties have been systematically investigated. X-ray diffraction (XRD) studies reveal the formation of cubic structure for perovskite and cubic spinel structure for ferrite phases with crystallite sizes in the range of 17.79–28.21 nm. Scanning electron microscope (SEM) analyses show that the boundaries between Ca-doped BaTiO3 (BCT) and La-doped Ni-Zn ferrite (NZLFO) phases are very clear which indicates small atomic diffusion. The average grain size was found to vary from 2.27 to 0.83 µm with increasing ferrite content. The M-H hysteresis loops obtained from vibrating sample magnetometer (VSM) measurements show as the content of the ferrite phase is increased the saturation magnetization and the remnant magnetization increase but the coercive field and thereby the magneto crystalline anisotropy energy decreases. High dielectric constant values are observed at low frequencies but it decreases with the frequency up to about 7 MHz and beyond which becomes frequency-independent. AC conductivity of the composites derived from dielectric constant and loss tangent values can be described by the hopping mechanism. [ABSTRACT FROM AUTHOR]

An efficient synthesis process approach based on a chemical solution route is developed for the cadmium selenide quantum dots (CdSe QDs) that utilise photonic and optoelectronic device manufacturing. The developed route consists of dissolving the cadmium chloride (CdCl2.H2O), 2-mercaptoethanol and sodium selenide anhydrous (Na2SeO3). The different characterisation parameters such as ultraviolet (UV) absorbance, x-ray diffraction (XRD), scanning electron microscopy, energy dispersive x-ray and transmission electron microscopy (TEM) were employed in order to develop the CdSe QDs. When the sample was analysed from the UV-visible studies, the bandgap was about 2.16 eV, whereas the bulk CdSe bandgap was about 1.78 eV. The developed CdSe QDs possessed a cubic crystal structure with crystalline dimensions of about 4.86 nm. Its surface morphology and structure showed the smooth appearance of the surface. The result indicated agglomerated spheres. Ultimately, according to XRD and TEM results, the crystalline dimension was determined in good agreements. [ABSTRACT FROM AUTHOR]

Cobalt ferrite nanoparticle (CFN) has received attention in magnetic resonance imaging (MRI) as a promising contrast agent due to its higher saturation magnetization and magneto-crystalline anisotropy. However, the in vitro cytotoxicity of CFN has raised concern for its biomedical application as a diagnostic agent. The coating of CFN by a biocompatible polymer such as chitosan (CH) might lessen the biocompatibility concern. Therefore, in this study, we examined the applicability of chitosan-coated cobalt ferrite nanoparticle (CCN) as an MRI contrast dye and investigated its biocompatibility in vivo . Phantom MRI images revealed that the relaxivity of CCN was 121 (±8) mM -1 s -1 , indicating the potential of CCN as a T 2 -weighted contrast agent. A single intravenous (iv) administration of CCN (10 mg/kg) improved the contrast of magnetic-resonance-imaging-based angiography (MRA) and brain-MRI in male albino Wistar rats compared to the control. Furthermore, toxicity studies dependent on dose (1-20 mg/kg) and time (1-28 days) in male albino Wistar rats confirmed the in vivo biocompatibility of CCN. The physical, hematological, biochemical, and histopathological observation assured that a single iv injection of CCN up to 20 mg/kg was well adjusted with liver, kidney, heart, and brain functions. The findings of the current study consolidate CCN as a promising candidate for MRI contrast dye.