We explored the impact of Gd doping on the structural, electronic and optical characteristics of the ZnO powder. The Gd-doped ZnO (0, 2% and 5%) powder samples have been synthesized using the conventional solid-state reaction process with varied Gd concentrations. The XRD pattern confirmed that all the studied samples are in the hexagonal wurtzite crystalline structure. The morphology has been explored using SEM images, which exhibited an agglomerated rod-like particle structure. The XPS results indicate the presence of oxygen vacancies (Vo) in the Gd-doped ZnO samples and the Vo’s are found to increase with increasing Gd amount. According to PL findings, the intensity ratio of the green and ultra-violet emission peaks is found to increase from 0.090 to 0.418 with increasing Gd-doping concentrations, confirming that Vo’s are increasing with Gd-doping. The UV-visible spectroscopy results reveal that the energy band gap (Eg) decreased from 3.31 eV to 3.23 eV with increasing Gd-doping concentration. Bangladesh J. Sci. Ind. Res. 58(1), 53-64, 2023

The present work focuses on developing Gd-doped Mn spinel nanoferrites and their potential application in the photodegradation of water pollutants. The impact of Gd3+ ion substitution on structural, electronic, and magnetic characteristics of manganese ferrites has been studied. Nanocrystalline samples of MnGdxFe2-xO4 (x = 0.0 to 0.10, in step size of 0.02) ferrites were prepared via sol–gel self-ignition route. The Rietveld, XPS, HRTEM, and SAED characterization methods confirmed the formation of phase pure ferrite nanoparticles ( 8–22 nm) in the cubic spinel structure. The Gd3+ content in these nanoferrites responded to a systematic reduction in the size of nanocrystallites and an upsurge in the density of nanoferrites. The XPS study revealed fine assimilation of constituent elements in the fcc lattice and ruled out impurities in the nanoferrites. The Fe and the Gd ions were found to be in Fe3+ and Gd3+ states, respectively. While a major fraction of the Mn ions were found to be in the Mn2+ state, a small fraction of Mn4+ ions was observed on the surface of nanoparticles. The nanoferrites were found to exhibit a soft ferromagnetic state from 300 to 20 K limits. The highest saturation magnetization was observed for x = 0.02 (MS = 66.6 emu/g at 20 K). The observed magnetic properties can be understood with the competing (Fe3+ and Mn2+)A–O2−–[Fe3+, Mn2+, and Gd3+]B superexchange interactions and magnetocrystalline anisotropy. Due to the small band gap energy of Gd-doped Mn ferrites than that of the pure Mn ferrite, they have demonstrated excellent photocatalytic activity for the degradation of methylene blue (MB) dye under visible light illumination. As much as 96.35

Polycrystalline Zn1−xCuxO (x = 0.0, 0.02, and 0.05) samples have been prepared using the solid-state reaction procedure. The X-ray diffraction (XRD) patterns of the samples confirm that Cu ions are successfully included in the ZnO hexagonal wurtzite structure. Rietveld analysis of the XRD patterns confirms the phase purity of the synthesized samples and a slight variation in their lattice parameter upon Cu doping. The morphology study by scanning electron microscopy (SEM) depicts transfiguration with Cu doping. The existence of oxygen vacancies (Vo) in the Cu-doped samples is indicated by X-ray photoelectron spectroscopy (XPS). The magnetization measurements reveal the diamagnetic nature of pure ZnO while the Cu-doped samples depict a room-temperature ferromagnetic (RTFM) behavior. The 2

The current study unravels the structural, optical band gap and magnetic characteristics of rare-earth (RE) gadolinium (Gd) substituted CoGdxFe2-xO4 (x= 0.00 - 0.10, in the interval of 0.02) nanocrystallites synthesized by the sol-gel self-ignition route. The XRD analysis and Rietveld refinement confirmed the existence of a single cubic phase with a crystallite size of ~15-21 nm range, further confirmed by HRTEM results. SEM images confirmed the well-known nano-size morphology for all the samples. The magnetization measurements show a hard ferromagnetic nature for all specimens within the temperature range of 20-300K. Coercivity, remanent, and saturation magnetization monotonically increased with a reduction in temperature from 300K to 20K. UV-Vis absorbance results show that the band gap energy of CoFe2O4 nanoparticles (NPs) decreases with increasing Gd3+ ion doping and have band gap energy values of 2.47, 2.15, 2,02, 2.00, 1.43 and 1.95 eV for x= 0.00, 0.02, 0.04, 0.06, 0.08, 0.10, respectively in CoGdxFe2-xO4 nanoferrites. The present study reveals that structural, optical band gap and magnetic properties could be altered by monitoring the quantity of gadolinium in cobalt nanoferrites. Bangladesh J. Sci. Ind. Res. 57(3), 173-186, 2022

The current article explores the dielectric and electronic properties of cobalt ferrite nanoparticles with Gd substitution in a series CoGd x Fe 2-x O 4 (0 ≤ x ≤ 0.1, in step x = 0.02) synthesized by the sol–gel self-combustion way. All the samples were studied with Fourier transform infra-red (FTIR) spectroscopy, Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), and impedance (dielectric) analyzer. One absorption band (υ 1 ) was observed in FTIR measurements, which is the characteristic feature of spinel nanoferrites in fcc type structure. The presence of active Raman modes in Raman spectra at room temperature demonstrated single phase formation of cobalt nanoferrites with metallic–metallic and metallic–oxygen bonding vibrations in the tetrahedral and octahedral sites. XPS data analysis confirmed phase purity and revealed incorporation of Gd ion in the spinel fcc lattice. The valence states of Fe, Co & Gd atoms in all these nanoparticles are found as Fe 3+ , Co 2+ , & Gd 3+ . The dielectric constant and dielectric loss are measured in a broad frequency range of 100 Hz to 120 MHz. The dielectric constant reduces with a rise in Gd concentration and frequency. This study reveals that electronic and dielectric properties could be effectively tuned by varying concentrations of gadolinium in cobalt ferrite nanoparticles.

The aim of this study is to synthesize, characterize, and finally, electrical property measurement of the nano-particles of polycrystalline magnesium and iron ferrite doped with rare earth (RE) materials cerium and erbium (MgCe x Er y Fe 2-x-y O 4 ) with a series x = 0.4, 0.6, 0.8 and y = 0.6, 0.4, 0.2 systematically to understand the electro-transport behavior. These series are prepared by using the sol–gel auto combustion method maintaining the pH of the solution at 7, i.e., in neutral condition in order to maintain the desired dielectric material properties. These grown materials were made into pellets by applying minimum hydrostatic pressure and then silver coated for electric measurements. The dielectric behavior of the desired series is studied with varying frequencies from 100 Hz to 120 MHz, and the results obtained are discussed in terms of the resistance, admittance, susceptance, dielectric constant, dielectric loss, and tangent loss using an impedance analyzer. The variation behaviors with respect to frequency are discussed systematically in an exhaustive manner, and the studies indicate that these materials may have possible incorporation to fabricate microwave antennas to reduce energy losses and eventual applications.

SnSe (Tin Selenide) thin films were fabricated from the tin chloride and sodium selenosulphate precursors of Sn2+ and Se2− ions by Chemical bath deposition. The thin films of varying thickness from 80 nm to 180 nm, were grown on glass substrate. X-ray diffraction technique is used to find out structure and crystalline size of the desired film. Surface morphology &elemental composition of the deposited films are investigated with the help of scanning electron microscopy (SEM) and EDAX.

In this paper, the relaxation mechanism at a lower temperature in the Ni0.5Zn0.5Fe2O4 sample has been discussed in detail. The sol gel method has been used to prepare the Ni0.5Zn0.5Fe2O4 sample. The Rietveld refinement of XRD gives the cubic crystal structure (a = 8.39 angstrom) and average crystallite size similar to 40 nm. The EDAX technique confirms the elemental composition in the sample. The M-H loop shows the remanence and coercivity value at 5 K temperature which indicates that the magnetic domains are exist. The saturation magnetization at 5 T field is also decreasing with increasing temperature which supports that the thermal energy destroys the domain size. The ZFC & FC curves show the relaxation mechanism of at lower temperature. The 2H(m) value is decreasing with increasing temperature which suggests that the magnetic domain is decreasing with increasing temperature which support the relaxation at lower temperature.