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In this research work, the structural, optical, and magnetic properties of Ce _1−x Cu _x O nanoparticles have been reported. Solid state reaction technique was employed to synthesize the nanoparticle samples. The synthesized materials were analysed structural properties from x-ray diffraction (XRD) observed that the crystallite size increased from16.9 nm to 40.43 nm and the lattice constant increased with increase of Cu doping concentration, and the structural properties after doping confirm the absence of other phase and synthesized samples had a cubic structure. Using SEM and EDAX, the nanoparticles surface morphology and elemental composition in investigated. The nanoparticles have a spherical shape and approximately the expected stoichiometric ratio. The optical band gap of copper doped cerium oxide nanoparticles is calculated and found the band gap decreased with increased dopant concentration. Ce _1−x Cu _x O nanoparticles using photoluminescence (PL) analysis at excitation wavelengths of 350 nm revealed emissions of the violet, blue, green, and red regions within the range of 350–700 nm. Vibrating sample magnetometer was found that the samples were room temperature ferromagnetic in nature and strength of magnetic moment increased with increase of doping concentration.

In this work, the Zn(3–(x+y))FexNiyP2 (x = 0.02, y = 0.02, 0.05, 0.07, and 0.09) system was synthesized with varying dopant concentrations using the solid-state reaction technique. Synthesized nanoparticles were subjected to different characterizations such as X-ray diffraction spectrometer (XRD), Scanning electron microscopy (SEM), Energy dispersive X-ray analysis (EDAX), Ultraviolet–visible near-infrared region spectroscopy (UV–Vis-NIR), Photoluminescence (PL) and Vibrating sample magnetometer (VSM). The XRD patterns confirmed that all samples have a tetragonal structure without any further phases present. Lattice parameters increase from a = b = 8.021 Å, c = 11.404 Å to a = b = 8.158 Å, c = 11.450 Å with increasing dopant concentration. SEM studies revealed particles are agglomerated with the effect of dopant concentration. EDAX spectra found nearly expected stoichiometric ratios and involved only Zn, P, Fe, and Ni elements. In the diffused reflectance spectra, the optical band gap increases from 1.410 to 1.438 eV with increasing dopant concentration. The emission peaks reveal that all emission peaks are in the same wavelength location as a result of the dopant content with excited wavelengths 215 nm and 242 nm. At room temperature, the ferromagnetic behavior of both the pure and codoped samples was confirmed by VSM. It is discovered that as the dopant content rises, the magnetic moment increases from 0.0863 to 0.2021 emu/g. We have observed from our calculations, magnetically stable phases and it suggests that these compounds may be useful materials for semiconductor spintronic devices. [ABSTRACT FROM AUTHOR]

Manganese and iron (Mn–Fe) co-doped with zinc phosphide (Zn(3−(x+y)) MnxFeyP2, x = 0.02, y = 0.02,0.04,0.06, and 0.08) nanoparticles were synthesised by a solid-state method. Structural, morphological, composition, optical, photoluminescence, and magnetic properties were investigated. The characterization techniques such as XRD (X-ray diffraction), SEM (Scanning electron microscopy), EDS (Energy dispersive X-ray spectroscopy), UV-Vis–NIR spectroscopy (Ultraviolet–Visible near-infrared region), PL (Photoluminescence), and VSM (Vibrating sample magneto meter) were employed to explore the obtained nanoparticles. The XRD analysis revealed that co-doped samples showed a tetragonal structure and no secondary phase peaks were observed in the diffraction patterns. Lattice parameters increase from a = b = 8.0211 Å, c = 11.4048 Å to a = b = 8.1408 Å, c = 11.4629 Å with increasing dopant concentration. The SEM study revealed that the size of agglomerations slightly increases with increasing dopant concentration. The elemental analysis confirmed that all the Mn-Fe co-doped Zn3P2 nanoparticles are nearly stoichiometric. The diffuse reflectance spectra were used to calculate the optical bandgap of the Mn-Fe codoped Zn3P2 nanoparticles and it increased with increase of dopant concentration (1.412–1.425 eV). PL studies confirmed all emission peaks are in the same wavelength position and slight intensity changes with increasing dopant concentration. The M–H hysteresis loop of the pure and Mn-Fe co-doped Zn3P2 nanoparticles shows weak ferromagnetism changing to strong ferromagnetism with the increase in dopant concentration. Magnetic moment obtained from the present studies suggests that the Mn–Fe co-doped Zn3P2 nanoparticles may be a useful material in semiconductor spintronics. [ABSTRACT FROM AUTHOR]

Abstract: This investigation reports, the effect of the concentration of erbium and lead ions on the physical, structural and optical properties of lead borosilicate glasses. These glasses were synthesized by the melt quench method. In the synthesis, the concentration of the erbium (Er3+) ion was varied in the order of 0.0, 0.1, 0.5, 1.0 and 2.0 mol% and lead (Pb2+) ion was varied in the order of 30, 29.9, 29.5, 29 and 28 mol%. The glasses were analyzed using X‐ray diffraction (XRD), Fourier transform infrared (FT‐IR) and UV–vis–NIR spectroscopy. From XRD, the amorphous nature of lead borosilicate glasses was confirmed. The functional groups which were present in the glasses have been identified by analyzing the FT‐IR spectrum. From the absorption spectra, the oscillator strengths as well as the Judd–Ofelt (JO) intensity parameters were determined and compared with other hosts. The JO intensity parameters were further used to calculate certain radiative properties for the excited luminescent levels of Er3+ ion. From emission spectra, full width at half maxima (FWHM), stimulated emission cross‐sections (σe) and certain lasing parameters were evaluated and compared with reference host glasses. The lifetimes of 4I13/2 excited level of Er3+ ion have also been recorded and analyzed. The calculated and experimental lifetimes were compared in terms of quantum efficiencies. From the photoluminescence analysis, the erbium doped lead borosilicate glasses well suited for optical fiber amplifiers are discussed. [ABSTRACT FROM AUTHOR]

An effort was made to develop semiconductor oxide-based room temperature dilute magnetic semiconductor (DMS) thin films based on wide band gap and transparent host lattice with transition metal substitution. The Sn $_{\mathrm {1}-x}$ Ni $_{x}\textit {O}_{\mathrm {2}}$ ( $x\,= \mathrm {0.00, 0.03, 0.05, 0.07, 0.10, and \,0.15}$ ) thin film samples were prepared on glass substrates by flash evaporation technique. All the samples were shown single phase crystalline rutile structure of host SnO $_{\mathrm {2}}$ with dominant (110) orientation. The Ni substitution promotes reduction of average crystallite size in SnO $_{\mathrm {2}}$ as evidenced from the reduction of crystallite size from 40 (SnO $_{\mathrm {2}}$ ) to 20 nm (Sn $_{\mathrm {0.85}}$ Ni $_{\mathrm {0.15}}\textit {O}_{\mathrm {2}}$ ). In the energy dispersive spectra as well as X-ray photoelectron spectra of all the samples show, the chemical compositions are close to stoichiometric with noticeable oxygen deficiency. The crystalline films were formed by coalescence of oval-shaped polycrystalline particles of 100 nm size as evidenced from the electron micrographs. The energy band gap of DMS films decreases from 4 (SnO $_{\mathrm {2}}$ ) to 3.8 eV ( x $=$ 0.05) with increase of Ni content. The magnetic hysteresis loops of all the samples at room temperature show soft ferromagnetic nature except for SnO $_{\mathrm {2}}$ film. The SnO $_{\mathrm {2}}$ films show diamagnetic nature and it converts into ferromagnetic upon substitution of 3 % Sn $^{\mathrm {4+}}$ by Ni $^{\mathrm {2+}}$ . The robust intrinsic ferromagnetism (saturation magnetization, 21 emu/cm $^{\mathrm {3}}$ ). Further increase of Ni content weakens ferromagnetic strength due to Ni-O antiferromagnetic interactions among the nearest neighbour Ni ions via O $^{\mathrm {2-}}$ ions. The observed magnetic properties were best described by bound magnetic polarons model. [ABSTRACT FROM AUTHOR]

Cu doped CdSe powders were synthesized by solid state reaction method and studied the effect of Cu doping concentration on structural, optical and magnetic properties of the prepared samples. From XRD study it was found that the lattice constant increased with increase of Cu doping concentration. A clear blue shift was observed in the samples from optical studies. From the magnetic measurements, it was found that the samples were room temperature ferromagnetic in nature and strength of magnetic moment increased with increase of doping concentration. These synthesized powders are dilute magnetic semiconductors and are very promising candidates for 'Spintronic' device applications. [ABSTRACT FROM AUTHOR]

Iron-doped SnO diluted magnetic semiconducting powders (SnFeO, x=0.00, 0.03, 0.05, 0.07, 0.10, and 0.15) were synthesized by a simple solid state reaction followed by vacuum annealing and studied the effect of Fe dopant concentrations on structural, optical, and magnetic properties of the synthesized samples. From the X-ray diffraction, it was confirmed that the samples prepared at lower dopant concentrations were tetragonal in structure whereas the samples prepared at higher dopant concentration exhibited orthorhombic SnO and FeO phases along with tetragonal SnO structure. FT-IR spectrum has been used to confirm the formation of Sn-O bond. The optical band gap of the SnFeO powders was increased from 3.6 eV to 3.7 eV with increase of dopant concentration. Raman spectroscopy measurement revealed that the broadening of the most intense Raman peak observed at 630 cm with Fe doping, conforming that the Fe ions are substituted at the Sn sites in the SnO lattice. Vibrating sample magnetometer measurements confirmed that the SnFeO powders were ferromagnetic at room temperature. [ABSTRACT FROM AUTHOR]

Abstract: Cd1−x Cr x Te diluted magnetic semiconductor crystals were grown by vapor phase growth technique in the composition range of 0≤x≤0.05 and the effect of Cr doping on structural, morphological, optical and magnetic properties have been explored. X-ray diffraction analysis confirmed that all the grown crystals were zinc blende in structure without having any phase transition up to a Cr doping level of x=0.05. The lattice parameter decreased with increase in Cr doping level. Optical studies indicated that the optical band gap of the crystals decreased with the increase of Cr doping level. Magnetic properties were studied using vibrating sample magnetometer at room temperature and room temperature ferromagnetism was observed in all the Cr doped CdTe crystals. [Copyright &y& Elsevier]

Cu-doped In2O3 thin films were prepared using flash evaporation method at different Cu-doping levels. The effect of annealing was studied on the structure, morphology and optical properties of the thin films. The films exhibited cubic structure and optical transmittance of the films increasing with annealing temperature. The highest optical transmittance of 78 % was observed with band gap of 4.09 eV. [ABSTRACT FROM AUTHOR]