Increase In Doping Concentration Research Articles

A DFT+U Study of the Structural and Electronic Properties of Zinc Doped Anatase TiO2 Nanomaterial

This work reports a theoretical study on the structural and electronic properties of the anatase phase of titanium dioxide (TiO2) within the framework of density functional theory corrected for on-site coulomb interactions in strongly correlated materials (DFT+U). The exchange correlation was described by local density approximation (LDA). The optimized lattice parameters obtained for the pure anatase TiO2 agree with the experimental data. Our results revealed that, after the zinc doping, the structure didn't change but there was a little expansion in the volume of the pure material. It was found that the doped structure's stability increases as the concentration of the dopant increases, but all the doped structures are stable. However, introducing the zinc dopant has significantly reduced the band gap of the pure anatase by 80.7 %, 80 %, and 78.6 % due to 0.25, 0.5, and 0.75 doping concentrations, respectively. This implies that the band gap energy increases as the doping concentration increases.

Bi–Er–O pre-synthesized phase (Bi1-xErx)2O3 doped ZnO varistors with high nonlinear coefficient and low leakage current

The content of free oxygen Oad at the ZnO grain boundaries has an important impact on the double Schottky barrier and electrical properties of ZnO varistors. In this work, Bi–Er–O pre-synthesized (BE) phase (Bi1-xErx)2O3 (0.25 < x < 0.455) with high conductivity of Oad was prepared using Bi2O3 and Er2O3 as raw materials, and the effects of the BE phase doping on the phase, grain boundary properties, and electrical properties of ZnO–Bi2O3–Sb2O3–Co2O3–MnO2–Cr2O3–SiO2 varistors were studied. XRD analysis shows that the lattice constant of the BE phase (Bi1-xErx)2O3 is between (Bi0.75Er0.25)2O3 and BiErO3. With increasing doping content of the BE phase from 0 to 0.75 wt%, part of Er3+ still exists in the form of the BE phase (Bi1-xErx)2O3 at the ZnO grain boundaries, and its content increases with increasing doping content of the BE phase. The conductivity of Oad in (Bi1-xErx)2O3 is much higher than that in Bi2O3, resulting in the generation of a large number of negative O′ and O″ at the ZnO grain boundaries, and decreasing concentration of the intrinsic point defect zinc interstice Zni. So the donor concentration Nd decreases, the height of the grain boundary barrier increases, the depletion layer widens, and the electrical properties are improved. By analyzing the low-temperature permittivity spectra, it was calculated that with increasing doping content of the BE phase from 0 to 0.75 wt%, the concentration of oxygen vacancy VO• decreases inappreciably, but the concentration of zinc interstice Zni•• decreases by about 23%. When the doping amount of the BE phase is 0.75 wt%, the nonlinear coefficient α of the obtained ZnO varistors is 73.9 ± 0.6, and the leakage current density JL is only 0.3 ± 0.1 μA/cm2. This study provides an important reference for improving the electrical properties of ZnO varistors by manipulating the Bi-rich phase structure to improve the double Schottky barrier characteristics.

Band gap, ferromagnetic resonance and strong microwave absorption of BaFe12-2xZnxSnxO19 compounds and enhanced dielectric loss in BaFe12-2xZnxSnxO19/carbon nano tube composites

The forbidden bandgap energy, magnetic properties, natural ferromagnetic resonance and microwave absorption are studied on the Zn2+ and Sn4+ doped BaFe12-2xZnxSnxO19. The forbidden band gap of BaFe12-2xZnxSnxO19 increases with the increasing doping content x from 1.80 eV up to 1.97 eV. The coercive field, the anisotropy field and the magnetocrystalline constant of BaFe12-2xZnxSnxO19 decreases with the increasing doping. The natural ferromagnetic resonance is observed. The high permeability, accompanied with the ferromagnetic resonance, enables strong microwave absorption. BaFe10.4Zn0.8Sn0.8O19 has a wide effective microwave absorption bandwidth (RL≤-10dB) of 6 GHz with the material thickness below 2.5 mm in 11.4–17.4 GHz. The dielectric loss has little contribution to the excellent microwave absorption of BaFe12-2xZnxSnxO19. The BaFe12-2xZnxSnxO19/carbon nanotube (CNT) composites significantly increase the permittivity. The high dielectric loss and the high magnetic loss further improve the microwave absorption. With a very thin thickness of 1.8 mm, BaFe10.4Zn0.8Sn0.8O19/CNT has a bandwidth of 7.1 + GHz of 10.9–––18 + GHz. With the material thickness thinner than 3 mm, BaFe12-2xZnxSnxO19/CNT composites have very broad effective microwave absorption bandwidth of 11.4+, 10.7 and 10.7 GHz, with x = 0.6, 0.8 and 1.0, respectively. It illustrates that both BaFe10.4Zn0.8Sn0.8O19 and BaFe12-2xZnxSnxO19/CNT composites are very promising microwave absorbers.

Composition-dependent structure and bandgaps in HfxZr1−xO2 thin films

ZrO2 as a wide-bandgap semiconductor with high dielectric constant and ferroelectric properties has been extensively studied. To explore the impact of chemical doping on the structure and optical performance of ZrO2, HfxZr1−xO2 (x = 0, 0.25, 0.5, 0.75, 1) thin films were prepared through pulsed laser deposition. X-ray diffraction reveals that the orthorhombic phase (o) (111) gradually transforms into the monoclinic phase (m) (−111) with the increase in Hf content from 0 to 1. Furthermore, optical property analysis demonstrates an increase in the optical bandgap from 5.17 to 5.68 eV with the increase in Hf doping content. Density functional theory calculations and x-ray photoelectron spectroscopy suggest that the widening of the bandgap in HZO films is associated with the hybridization of Zr 4d and Hf 5d orbitals.

Multifunctional Ce+3 doped nickel-cobalt mixed ferrites via co-precipitation method for photocatalytic and antibacterial activity

The overuse of industrial dyes and anti-bacterial drugs are destroying fresh water reservoirs and making bacteria more resistant, respectively. To sort out these problems, we have synthesized Cerium doped Nickel-Cobalt mixed ferrites (Ce-@NCMF) with chemical composition [Ni0.4Co0.6CexFe2-xO4 (where x = 0.00, 0.10, 0.15, 0.20 and 0.25)] via co-precipitation method. Influence of cerium doping on the structural, optical, electrical, magnetic, photocatalytic and anti-bacterial properties of Ce-@NCMF studied. Powder x-ray diffraction analysis (PXRD) confirmed the synthesis of Ce-@NCMF. Decrease of crystallite size from 29.71 to 24.95 nm was observed with increase in dopant concentration. Tauc’s plot indicated the decrease of energy bandgap from 2.10 to 1.89 eV with increase in dopant concentration, which revealed the absorption of light in visible region to generate electron–hole pairs for photocatalytic applications. FTIR spectra indicated the presence of M-O bonds as major functional group present in Ce-@NCMF. Electrical properties demonstrated the prominent increase of electrical conductivity with increase of Ce-doping. VSM analysis was performed to analyse the magnetic properties of materials and showed prominent decrease in saturation magnetization value from 84.66 to 19.85 emu g−1. Owing to optical bandgap in the visible region, all the synthesized samples were evaluated for their photocatalytic potential for the degradation of methylene blue. Ce-@NCMF at x = 25% dopant value showed maximum degradation efficiency (95%) under sunlight irradiation of 90 min. Kinetic studies of dye degradation followed pseudo-1st order kinetics with maximum rate constant (k) value of 2.78×10−2 min−1. Antibacterial activity results showed the bioactive nature of Ce-@NCMF against all strains of bacteria in consistent with the crystallite size of samples. Smallest crystallite size Ce-@NCMF were found most active against gram-negative bacterial strains.

Display and energy storage applications of copper doped nanoceria

In the current study CeO2: Cu2+ (0–11 mol%) NPs were synthesized by Aloevera mediated solution combustion method followed by calcination. The synthesized samples were described and their multifunctional characteristics, including photoluminescence, sensor, and supercapacitor features were covered thoroughly. Bragg reflections confirmed single-phased CeO2: Cu2+ NPs with cubic spinel structure belonging to space group Pm3m(221). Crystal size was estimated using both the Scherrer and W-H plot method. The energy gap was computed from the Wood-Taucs relation. The crystallite size increases whereas the energy band gap increases with an increase in dopant concentration. The photoluminescence emission peaks of CeO2:Cu2+ (1–11 mol%) NPs, CIE, and CCT λex= 340 nm unambiguously show that the current nanophosphor might be a promising nanophosphor material for white and blue LEDs. The Cyclic voltammetry analysis was performed on as obtained CeO2: Cu2+ NPs for oxidation and redox peaks. EIS revealed that ion transport kinetics and super-capacitance values were obtained from GCD analysis. Specific capacitance values are found to be in the range 18 to 61 F/g for CeO2: Cu2+ 1 to 11 mol % NPs respectively which are in good agreement with the values obtained from CV analysis. Thus, the present synthesized material might find applications in the field of display technology and energy storage materials.

High-efficiency TOPCon solar cell with superior P + and P++ layer via one-step processing

The boron diffusion process in the front field of N-type tunnel oxide passivated contact (TOPCon) solar cells is crucial for PN junction formation and the creation of a selective emitter. This study presents a theoretical model of boron diffusion in silicon using molecular dynamics. The research examines the mean square displacement and diffusion coefficient of boron atoms at varying temperatures, confirming their diffusion behavior. The simulations indicate predominant boron diffusion in the z-direction within the silicon matrix, with the diffusion depth being temperature dependent. The optimal temperature range for boron diffusion in silicon is identified as 950 °C to 1050 °C. Using boron-doped silicon paste and boron trichloride as dopants, thermal diffusion experiments were conducted to fabricate the front-field PN junction (p+ layer) and selective emitter (p++ layer) by one step. Subsequent processing and performance evaluation were performed on a production line. Experimental findings reveal a decrease in boron diffusion at higher temperatures, reduced sheet resistance, increased doping concentration, and deeper junction formation. The ideal boron concentration in the p+ layer is 8.68 × 1018 atom/cm3 with a depth of 0.53 μm, while the p++ layer is 2.35 × 1019 atom/cm3 and 0.82 μm. The efficiency of the optimized TOPCon + cell production line reaches up to 25.17 %, marking an improvement of 0.23 % over the standard cell production line. This research contributes to elucidating the mechanism of boron diffusion and offers insights for enhancing the efficiency of TOPCon solar cells.

Effect of nickel doping on magnetic and dielectric properties of orthorhombic calcium ferrite nanoparticles

Nickel (10∼50 mol%) doped calcium ferrite nanoparticles (NPs) are synthesized by the solution combustion method using lemon juice extract as a reducing agent, followed by calcination at 500°C. The calcined samples are characterized with different techniques. The Bragg reflections of Nickel doping confirm the formation of a single orthorhombic calcium ferrite phase. The crystallite size is estimated using both Scherrer's and the W-H plot method. The surface morphology consists of irregular size and shaped agglomerated NPs along with pores and voids. A blueshift and a broad absorption spectrum is observed with an increase in the direct energy band gap. The direct energy band gap estimated from Wood and Tauc's relationship was found to be 2.91∼2.97 eV with an increase in dopant concentration. The magnetic analysis provided values for saturation magnetization (Ms), remanence (Mr), and coercivity (Hc), while dielectric studies demonstrated a dielectric constant of 2.81, 2.14, and 1.67 with increasing dopant concentration. The variation of dielectric properties of the sample as a function of frequency in the range 0.1∼20 MHz has been studied at room temperature. The dielectric properties of CaFe2O4: Ni (1∼9 mol%) NPs clearly indicate that there is a more pronounced dispersion at lower frequencies, gradually reaching saturation as the frequency increases. The dielectric loss was found to decrease from 4.62, 3.22, and 2.32 with an increase in Ni2+ substitution (10, 30, and 50 mol%) respectively. These results indicate the suitability of these samples for applications in memory devices and high-frequency applications.

Effects of manganese doping on the lattice structure and iron ion states in La2/3Ca1/3Fe1-xMnxO3-δ

In this paper, La2/3Ca1/3Fe1-xMnxO3-δ(x = 0–0.6) nano particles have been prepared by the sol-gel method. X-ray diffraction (XRD) analysis revealed that with the increase of Mn doping content, the main diffraction peak shifted to the right, the lattice parameters decreased overall, and the degree of lattice distortion gradually reduced. X-ray photoelectron spectroscopy (XPS) analysis indicates that the valence states of Fe and Mn in the system coexist as trivalent and tetravalent, and with the increase in Mn doping, the ratio of Fe3+/Fe4+ decreases, while the ratio of Mn3+/Mn4+ slightly increases. The results of Mössbauer spectrum analysis revealed that as the Mn doping content increased, some Fe ion valence states in the system gradually changed from Fe3+ to Fe4+, and the presence of the paramagnetic phase became increasingly prominent. Furthermore, with the increase of Mn doping content, the degree of lattice distortion in the system decreased, which is consistent with the results obtained from the XRD analysis. This work will provide a reference for future research on the effects of manganese doping in similar systems.

Preparation and photoluminescence study of rare-earth-free red emitting La3Ga5SiO14:Mn4+ phosphors

Given the growing interest in eco-friendly lighting solutions, the use of high-quality phosphors has become integral to the advancement of all-solid white light-emitting diodes (WLEDs). One novel phosphor, La3Ga5SiO[Formula: see text]:Mn[Formula: see text] (LGS), has been successfully synthesized via a high-temperature solid-state reaction. The crystal structure of LGS is classified as belonging to the trigonal phase, with a space group P321. The excitation spectrum exhibits a wide peak within the wavelength range of 280–440 nm. It emits a highly intense red light, with a peak emission occurring at 715 nm within the spectral range of 670–740 nm is attributed to the transition of Mn[Formula: see text] from 4A2g to 4T2g. LGS:Mn[Formula: see text] demonstrates a favorable quantum efficiency of 16% when doped with a concentration of 0.25 mol% Mn. The decay curve of LGS:Mn[Formula: see text] exhibits a pattern of decreasing lifetime as the dopant concentration increases. Additionally, the LGS:Mn[Formula: see text] products demonstrate a CIE chromaticity of (0.688, 0.2644), which is located within the deep red light region. All the aforementioned findings support the potential application of LGS:Mn[Formula: see text] specimens in WLEDs, thereby contributing to the progress of environmentally friendly and energy-efficient lighting.

Influence of Hf doping on structural, morphological, optical and electrochemical properties of NiO thin films: Electrochromic application

In this study, the authors investigated the influence of hafnium doping on the properties of NiO thin films using the spray pyrolysis (SP) method. A comprehensive analysis was conducted to evaluate the structural, morphological, optical, and electrochemical characteristics of the deposited films. Techniques such as X-ray diffraction analysis (XRD), Raman spectroscopy, scanning electron microscopy (FESEM), energy dispersive analysis by X-ray (EDS), UV–Vis–NIR spectrophotometry, cyclic voltammetry (CV), and chronoamperometry (CA) were employed. XRD examination revealed that the NiO thin films exhibit a polycrystalline cubic phase, with a preferred orientation along the (111) plane. The successful integration of Hf ions into the NiO matrix was confirmed by the Raman spectrum. SEM images depicted the formation of dense and uniform nanograins on all film surfaces, free from any cracks. EDS analysis and elemental mapping indicated uniform and homogeneous distribution of Ni, O, and Hf elements across the films. The optical analysis suggested a decrease in the optical band gap energy from 3.54 eV to 3.49 eV with an increase in hafnium doping concentration. Electrochemical results revealed a continuous improvement in specific capacitance with Hf doping. The NHf6 sample reached 65 F. g−1 at 5 mV s−1, compared to 46 F. g−1 at 5 mV s−1 for the NHf0 sample. However, the NHf4 film exhibited the highest optical density variation (49%), shortest response times (tb = 3.58 s, tc = 4.67 s), and the largest coloration efficiency (63.39 cm2/C), indicating enhanced electrochromic performance at this Hf doping rate. These findings suggest that Hf-doped NiO holds promise as a candidate for use as a counter-electrode in electrochromic devices.

Enhanced Photo/Electrocatalytic Hydrogen Evolution by Hydrothermally Derived Cu-Doped TiO2 Solid Solution Nanostructures.

Highly efficient nanocatalysts with a high specific surface area were successfully synthesized by a cost-effective and environmentally friendly hydrothermal method. Structural and elemental purity, size, morphology, specific surface area, and band gap of pristine and 1 to 5% Cu-doped TiO2 nanoparticles were characterized by powder X-ray diffraction (PXRD), X-ray photoelectron spectroscopy (XPS), electron paramagnetic resonance (EPR), energy dispersive X-ray analysis (EDAX), inductively coupled plasma mass spectrometry (ICP-MS), liquid chromatography-high resolution mass spectrometry (LC-HRMS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), BET surface area, Raman spectroscopy, photoluminescence spectroscopy (PL) and UV-visible diffused reflectance spectroscopy (UV-DRS) studies. The XPS and EPR findings indicated the successful integration of Cu ions into the TiO2 lattice. UV-DRS and BET surface area investigations revealed that with an increase in dopant concentration, Cu-doped TiO2 NPs show a decrease in band gap (3.19-3.08 eV) and an increase in specific surface area (169.9-188.2 m2/g). Among all compositions, 2.5% Cu-doped TiO2 has shown significant H2 evolution with an apparent quantum yield of 17.67%. Furthermore, the electrochemical water-splitting study shows that 5% Cu-doped TiO2 NPs have superiority over pristine TiO2 for H2 evolution reaction. It was thus revealed that the band gap tuning with the desired dopant concentration led to enhanced photo/electrocatalytic sustainable energy applications.

Effects of Rare-Earth Elements Doping on Micro-Structure and Fluorescence Performances of Fluorapatite

For purposes of optimizing the microstructure and fluorescence properties of rare-earth elements (REEs)-doped fluorapatites (FAps), various kinds of REEs (La, Pr, Sm, Eu, Gd, Ho, Er, and Yb) with the concentration of 2~20 mol.% have been inserted into the FAps framework via hydrothermal method, in order to investigate the influential mechanism of the REEs on the crystal structure, morphology, and fluorescence under the excitation of the near-ultraviolet light of the FAps. Experimental results show that the wavelength of the emitted light of the REEs-doped FAps is decided by the type of REEs. Unlike the Pr/Yb- and Ho-doped FAps and with the fluorescence of red and green emitted light, respectively, the Er-doped FAps show a blue light emission with wavelengths of 296, 401, and 505 nm, which is, moreover, different with the Eu-doped Faps, showing an orange light emission with wavelengths of 490, 594, and 697 nm. The emission luminous color is related to the lattice defects of the FAps doped with the various types and the effective doping concentration of the REEs. The luminous intensity increases with the increase in the effective doping concentration of the REEs. Nevertheless, the formation of rare-earth fluoride results in the decrease in the effective doping concentration of the REEs and the luminous intensity. The FAps with an effective doping concentration of 7 mol.% Er and 3 mol.% Eu show relative excellent fluorescence properties.

First-principles study on the effects of Zr doping and interstitial H and O vacancy on the optoelectronic properties of β-Ga2O3

In this work, the electronic structure and optical properties of Zr-doped [Formula: see text]-Ga2O3 with interstitial H and O vacancies were studied by using first-principles generalized gradient approximation combined with the Hubbard U method based on density functional theory. The energy band structure, density of states, absorption spectrum, effective mass, mobility and conductivity of the doped system were calculated and analyzed. Results showed that the doped system was more stable under the Ga-rich condition than under the O-rich condition. With the increase in Zr doping concentration, the bandgap of the [Formula: see text]-Ga2O3 system gradually narrowed and the absorption spectrum of the system blue-shifted in the wavelength range of 162–275[Formula: see text]nm. System conductivity was enhanced by Zr doping, decreased by O vacancies and greatly improved by interstitial H. Therefore, doping Zr into the [Formula: see text]-Ga2O3 system is important for improving material properties and preparing electronic and optical devices.

Blue-Emitting SrLaAlO&lt;sub&gt;4&lt;/sub&gt;: Ce Phosphors Obtained by Combustion Synthesis

In this study, a simple combustion synthesis was utilized to obtain the SrLaAlO4 (SLAO) host sample and SrLaAlO4: Ce (SLAO:Ce) phosphors with different Ce concentrations (1.0, 3.0, 5.0 and 7.0 mol.%). Also, the as-synthesized samples were subjected to a post-annealing treatment at 1200 °C in air. X-ray diffraction (XRD) patterns for the SLAO and SLAO:Ce phosphors correspond to pure tetragonal phase (JCPDS No 24-1125). The photoluminescence spectra of the SLAO:Ce phosphors (under 254 nm excitation) showed a blue emission peak at 470 nm attributed to the 5d → 4f Ce3+ transition. The SLAO:Ce phosphors doped with 1 mol.% of Ce showed the highest emission and quenching of photoluminescence was produced when the Ce dopant concentration increases (3.0-7.0 mol.%). The CCT and color purity are in the range of 6456 -8276 K and 49.1 -55.9 % respectively. Due to its strong blue emission, the SLAO:Ce phosphor could be a good candidate for UV phosphor converted LED or for solid state lighting applications.

Optical and electrical properties of Ni+2 doped nanocrystalline Bi2S3 thin films prepared by chemical bath deposition method

Nickel (Ni+2) doped nanocrystalline Bi2S3 thin films are deposited on the glass substrate from the solutions containing Bismuth Nitrate, Ethylenediamine Tetraacetic acid (EDTA) and Thioacetamide at a bath deposition temperature of 318K. The optical, surface morphological and electrical properties of Ni-doped Bi2S3 thin films prepared at three different doping concentration are investigate by using ultraviolet–visible transmission spectra (UV–Vis), Scanning electron microscopy (SEM), Energy Dispersive X-ray (EDAX) and thermo-e.m.f. techniques. The optical band gap energies are found in between 2.32-2.43 eV. The SEM images show that the prepared films are continuous, dense and distributed over the entire area with good uniformity. The electrical conductivity of the films are in the order of 10-2 Ω-1 m-1 . The films are n-type as determined from the Hot Probe method. Photoconductivity studies reveal that photocurrent increases with the increase in Ni doping concentrations. Due to the absorption of photons, free electron-hole pairs (EHP) are produce.

The effect of SiC on the growth habit of Fe-Ni-C system Ib gem grade diamond crystals

This article investigates the influence of different silicon carbide contents on the morphology and quality of diamond single crystals synthesized in the Fe-Ni-C-Si system under high temperature and pressure environments. It was found that silicon successfully entered the diamond lattice through bonding. As the doping concentration increases, the growth rate of diamond crystals decreases and defects appear on the crystal surface. The increase in internal stress in the lattice reduces the quality of diamond, as evidenced by the shift in Raman peak and half peak width of the diamond. Moreover, the infrared characterization results showed that the nitrogen element in the crystal exists as a single atom (C-center) in the diamond crystal, and the nitrogen content decreases with the increase of SiC content. This work provides insights for understanding the growth mechanism of natural diamonds and enriching the application of silicon doped diamond single crystals.

High bias stability of Hf-doping-modulated indium oxide thin-film transistors

Device stability is one of the key parameters for transistor applications. To improve the stability of Indium oxide (In2O3) after a long-time gate bias, a synthetic solution of hafnium chloride (HfCl4) and indium nitrate (In(NO3)3∙xH2O) reagents were used to obtain 0% to 5-at.% Hf doped In2O3 thin-film transistors. With the increase of Hf doping concentration, oxygen vacancies and residual hydroxyl groups continue to decrease, suppressing the carrier concentration and influencing the trap state density of In2O3. The sub-threshold slope (SS) 0.78 V·dec−1 for the undoped In2O3 transistor in this work is a typical value. When the dopant dose is up to 5-at.%, SS decreases to 0.32 V·dec−1. According to the proportional relationship between SS and the density of trap states, it shows that the density of trap states in the dielectric layer and the semiconductor/dielectric interface SS is greatly reduced after 5-at.% Hf doping. The probability of the charge being trapped is dropped as well. At the same time, under the doping of Hf, the transistor exhibits a very small threshold voltage shift. Especially at the dopant dose of 5-at.%, the transfer characteristic curve hardly shifts. This work demonstrates an In2O3 transistor with high bias stability by doping method.

Exploiting the Bi-doping effect on the properties of NaNbO3 perovskite -type materials

In this work, Bi3+ doped NaNbO3 materials have been prepared successfully by the hydrothermal method at low temperature and pressure. The influence of Bi3+ dopant on the structural, morphological/optical properties of NaNbO3 nanomaterials is investigated. The perovskite-type structure for the pristine and doped samples is characterized within the orthorhombic structure and the unit cell parameteres increase as the dopant concentration increases. The σDC conductivity for the investigated samples shows that 3 % of Bi induces a decrease from 9.26 10–5 S/m to 3.27 10−5 S/m and the obtained results for the conductivity were interpreted taking into account VRH and CBH theoretical models.

Structural, optical and magnetic properties of Cu doped CeO2 nano powders synthesized by solid state reaction

In this research work, the structural, optical, and magnetic properties of Ce1−xCuxO 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. Ce1−xCuxO 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.