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In this work, the ZnAl2O4: Eu, Dy phosphor prepared by urea fuel combustion method. The efficient ZnAl2O4: Eu, Dy phosphor was characterized by several characterization techniques. Surface area was found 32.785 m2/g by BET surface area analyser. Structural, optical and morphological information investigated by XRD, SEM, Photoluminescence properties were studied by excitation and emission (λex.=350 nm and λem.=495 nm) spectra. The phosphors showed broad blue luminescence around 450 nm to 500 nm due to the Eu (II) ions (1 mol %) and phosphor also gave weak emission at 570, 578, and 596 nm in red region due to Eu (III) ions. The PL intensity were decreased as well as shift toward the lower wavelength (∼450 nm) from the higher wavelength (yellow-red region) with the corresponding concentration of Europium and Dysprosium ions in the ZnAl2O4:Eu, Dy. The obtained zinc aluminate phosphors have higher luminescence efficiency due to high purity and perfect spinel crystallinity of material. ZnAl2O4:Eu, Dy Nano phosphor would be widely used in plasma display panel (PDP) as a blue emitting phosphors, mercury excited lamp, and solid state lighting devices etc.

The rare earth doped aluminates and standard phosphor CaSO4:Dy were synthesized by urea fuel combustion and co-precipitation method respectively. The low-resolution SEM micrographs that the powders show many agglomerates. In order to confirm the chemical homogeneity of the phosphor sample by EDX spectra. The EDX study of the phosphors were confirmed the presence of doping rare earth metal Eu and Dy in host matrix compounds. The phosphors ZnMgAl10O17:Eu, BaMgAl10O17:Eu,Dy, SrMgAl10O17:Eu, Dy, CaMgAl10O17:Eu, Dy, BaMgAl10O17:Eu, and BaMg2Al16O27:Eu shows prominent TL peak near ∼187 °C and its intensity is higher as compared to CaSO4:Dy TLD phosphor. The glow curves for these hexa-aluminate samples are nearly identical. In short, the TL-intensity is found to be comparable and higher with that of CaSO4:Dy. Therefore, the reported aluminate samples having good intensity would be further investigated in respect of dose dependence, and then it may be used as TLD phosphors of ionization radiations.

Synthesized Combustible phosphor were characterized by SEM (EDX), and Thermo-luminescence spectroscopic reader. Thermo-luminescence (TL) glow curve recorded after 10 minutes UV (254 nm) irradiation of the efficient sample Zn0.97Al2O4:Eu0.01, Dy0.02 sample. The TL intensity verses corresponding concentration of Europium and Dysprosium in ZnAl2O4:Eu, Dy were plotted and found the various peak shifting and adjusting information between two peaks of zinc aluminate. After that efficient sample also efficient for 30 mins irradiation of the UV dose. The Glow peak parameters and Thermo-luminescence parameters [activation energy (Eav =0.366 eV), frequency factor (Sav. = 3.083×103 Sec−1)] were calculated by Chens-equation. The obtained zinc aluminate phosphors have higher luminescence efficiency due to high purity and perfect spinel crystallinity of material. ZnAl2O4:Eu, Dy Nano phosphor would be widely used in plasma display panel (PDP) as a blue emitting phosphors, mercury excited lamp, and solid state lighting devices etc.

Multiferroic nanoparticles of Bi1-xDyxFeO3 (x=0 and 0.10) have been prepared by sol-gel method and the variation in their structural, morphological and magnetic properties has been studied. Structural analysis reveals distortion of rhombohedral lattice of BiFeO3 by the substitution of Dy3+ions. The shift observed in the diffraction peaks with Dy3+ ions indicates its successful substitution. The morphological analysis shows the formation of agglomerated nanoparticles having average particle size 25 and 18 nm for undoped and Dy-doped BiFeO3 nanoparticles, respectively. The observed agglomeration is due to high surface energy of synthesized nanoparticles. Magnetic studies confirm typical ferromagnetic behavior for the synthesized nanoparticles. Enhancement in saturation magnetization values with Dy-substitution is attributed to suppression of spin cycloid structure by the reduction in particle size, lattice distortion and surface induced magnetization.

The Zn-Mg ferrite samples of general formula Zn0.5Mg0.5Fe2-xDyxO4 (where x =0.0, 0.01, 0.05, 0.10) have been prepared from high purity oxides by using standard solid state reaction technique. X-ray diffraction analysis shows the formation the samples in the cubic phase at room temperature with space group Fd3m. it is observed that lattice parameter is increases and crystallite size decreases with the substitution of Dy3+. The dielectric measurements were carried out at room temperature as a function of frequency. The experimental results reveal that dielectric constant and dielectric loss decrease as frequency increases.

Dysprosium (Dy) doped ZnO and Ytterbium (Yb) doped ZnO nanoparticles were successfully synthesized by simple solution method. The structural, morphological, optical and magnetic properties of synthesized samples have been investigated by various techniques, including X-ray diffraction (XRD), UV-absorption spectroscopy, photo luminescence spectroscopy, and vibrating sample magnetometer. X-ray diffraction analysis confirmed the formation of pure single phase with a particle size in the range of 20–31nm. Optical absorption studies demonstrates that the absorption edge of the Dy:ZnO and Yb: ZnO nanoparticles appeared to shift towards the longer wavelength due to the charge transfer between the ZnO valence or conduction band and rare earth ion 4f energy level. The band gap of the doped ZnO samples was found to be blue shift and it varies from 3.2eV-3.05eV due to the quantum confinement of the charge carriers in ZnO. M agnetic measurements studies indicates that Dy and Yb doped ZnO nanoparticles show weak ferro...

Polycrystalline samples of NaBaBO3:Dy3+ were prepared by employing modified solution combustion synthesis method. The phase formation was confirmed by X-ray powder diffraction (XRD) measurements. The prepared sample was characterized by using SEM and FTIR Techniques. The photoluminescence excitation and emission spectra were measured on HITACHI F-7000 fluorescence spectrometer. Under the excitation of near-UV light, Dy3+ doped NaBaBO3 presents the PLE spectra show the excitation peaks from 300 to 400 nm is due to the 4f–4f transitions of Dy3+. This mercury-free excitation is useful for solid state lighting and light-emitting diodes. The emission of Dy3+ ions upon 350 nm excitation is observed at 482 nm due to the 4F9/2→6H15/2 transitions and 574 nm due to 4F9/2→6H13/2 transitions. The CIE chromaticity coordinates for NaBaBO3:Dy3+ phosphors are simulated and located in the bluish-white region. The phosphor shows an excellent thermal stability on temperature quenching effects. The effect of concentration of Dy3+ ions on the PL intensity has also been investigated. It has been observed that the powder sample exhibits highest PL emission intensity for Dy3+ concentration of about 0.01 moles. The results were discussed on the relationship between the structure and the luminescence properties.

Ce and Dy doped Cobalt ferrites with the chemical composition CoCexDyxFe2-2xO4 (x = 0.00 and 0.04) were synthesized via the chemical route using citrate-gel auto-combustion method. The structural analysis has been carried out with the help of x-ray diffraction (XRD). Formation of spinel cubic structure of the ferrites was confirmed by XRD analysis. Mossbauer spectra were recorded for both samples at room temperature. Presence of the well resolved sextet spectra corresponding to A and B sub-lattice clearly shows that both the samples have ferrimagnetic ordering at room temperature. Isomer shift observed from fitting of the Mossbauer spectra infers that Fe3+ ions are in high valence state. The decrease in the hyperfine field due to the doping of Ce and Dy clearly showed that magnetic interactions diluted due to the doping of Ce and Dy ions.Ce and Dy doped Cobalt ferrites with the chemical composition CoCexDyxFe2-2xO4 (x = 0.00 and 0.04) were synthesized via the chemical route using citrate-gel auto-combustion method. The structural analysis has been carried out with the help of x-ray diffraction (XRD). Formation of spinel cubic structure of the ferrites was confirmed by XRD analysis. Mossbauer spectra were recorded for both samples at room temperature. Presence of the well resolved sextet spectra corresponding to A and B sub-lattice clearly shows that both the samples have ferrimagnetic ordering at room temperature. Isomer shift observed from fitting of the Mossbauer spectra infers that Fe3+ ions are in high valence state. The decrease in the hyperfine field due to the doping of Ce and Dy clearly showed that magnetic interactions diluted due to the doping of Ce and Dy ions.

Environmental radiation dose measurement needs to be done to ensure that the radiation exposure received by the community is still under the dose limit specified by BAPETEN (Badan Pengawas Tenaga Nuklir - Nuclear Power Supervisory Agency). One of the measurement methods is using CaSO4 as the dosimeter. The addition of dopant increases the luminescence ability of CaSO4. Dy and Tm are the effective dopants for TLD CaSO4. Co-precipitation is one of the methods which can be used to add a dopant. Therefore, the aim of this research is to know the influence of the Dy and Tm dopants addition in the TLD synthesis using CaSO4 by co-precipitation method. Based on the results, it can be concluded that the addition of Dy and Tm dopants increases the sensitivity of CaSO4. TLD from the experiment has a linear response against the radiation dose.

The present study has been carried out to investigate the effect of Co doping on structural and optical properties of Dy doped ZnO nanoparticles. We have prepared pure Zinc oxide, Dy (1%) doped ZnO and Dy (1%) doped ZnO co-doped with Co(2%) with the help of simple sol-gel combustion method. The structural analysis carried out using X-ray diffraction spectra (XRD) indicates substitution of Dy and Co at Zn site of ZnO crystal structure and hexagonal crystal structure without any secondary phase formation in all the samples. The surface morphology was analyzed by transmission electron microscopy (TEM). Absorption study indicates that Dy doping causes a small shift in band edge, while Co co-doping results significant change is absorption edge as well as introduce defect level absorption in the visible region. The band gap of samples decreases due to Dy and Co doping, which can be attributed to defect level formation below the conduction band in the system.The present study has been carried out to investigate the effect of Co doping on structural and optical properties of Dy doped ZnO nanoparticles. We have prepared pure Zinc oxide, Dy (1%) doped ZnO and Dy (1%) doped ZnO co-doped with Co(2%) with the help of simple sol-gel combustion method. The structural analysis carried out using X-ray diffraction spectra (XRD) indicates substitution of Dy and Co at Zn site of ZnO crystal structure and hexagonal crystal structure without any secondary phase formation in all the samples. The surface morphology was analyzed by transmission electron microscopy (TEM). Absorption study indicates that Dy doping causes a small shift in band edge, while Co co-doping results significant change is absorption edge as well as introduce defect level absorption in the visible region. The band gap of samples decreases due to Dy and Co doping, which can be attributed to defect level formation below the conduction band in the system.

A persuasive and thriftily feasible homogeneous co-precipitation route was adopted to fabricate dysprosium (Dy) doped zinc ferrite (Zn1−xDyxFe2O4)nanoparticles in order to examine their structural, optical and magnetic properties. Theas-synthesized Zn1−xDyxFe2O4 was studied for its momentous applications in photo-degradation of organic Methylene Blue (MB) dye. The paper marksthe connotation of zinc ferrite nanocatalyst in Photo-Fenton degradation. The chemical composition of dysprosium has a decisive feature of this research work. From X-ray diffraction analysis (XRD), spinel phase formation of theas-synthesized Zn1-xDyxFe2O4 nanoparticles was observedand the crystallite size was foundto increase as the doping concentration increased. Theabsorption bands peaked between 600-400 cm−l waspragmatic by Fourier Transform Infrared spectral analysis (FTIR). Transmission Electron Microscopy (TEM) micrograph elucidated the morphology and the speck size of as-synthesized nanoparticles. Surface area and pore size were determined by Brunauer-Emmett-Teller (BET) technique.

We report here the coercivity (Hc) enhancement by way of surface diffusing Dy into the sintered Nd-Fe-B magnets, employing a novel and simple vapor deposition method. The beneficial effect on coercivity and the ominous effect on remanence were both studied and correlated with the time dependent Dy diffusion. The coercivity of Nd-Fe-B magnet is improved by partial substitution of Dy for Nd and described here is the surface diffusion method adopted to infiltrate Dy in to the sintered Nd-Fe-B magnet and the consequential effect on the microstructure and the magnetic properties. An 80% improvement in Hc occurred for four hours of Dy diffusion, while encountering a fall of about 11% in remanence. The SEM-EDS analysis brought out that Dy partition to a higher degree in to the Nd-rich grain boundary phase than the matrix Nd2Fe14B.

A novel lanthanide-nitronyl nitroxide compound Dy (hfac)3(NTT-Ph-4-OH)2 (1) has been successfully synthesized by the reaction of NTT-Ph-4-0H with Dy (hfac)3. Single crystal X-ray crystallographic analysis reveals a mononuclear coordination of complex 1. The magnetic studies reveal that complex 1 shows very weak ferromagnetic interaction between Dy (TTT) ion and the coordinated nitronyl nitroxide.

Effect of dysprosium (Dy) as a dopant on structural, morphological and gas sensing properties of zinc oxide has been studied in the present work. A chemical route was adopted for synthesis of pure and Dy doped zinc oxide. Synthesized samples were characterized using X-ray diffraction, field emission scanning electron microscope, Branneur Emmet Teller and X-ray photoelectron spectroscopy. XRD studies confirmed the hexagonal wurtzite structure of pure and doped samples and the lattice constants and unit cell volume were calculated using Rietveld refinement. Gas sensors were fabricated from synthesized samples and it has been found that Dy doping has significantly improved sensor response towards ethanol. In addition, reduction in optimum operating temperature has been achieved from 400 to 300°C because of doping. The improved sensor properties in doped sensor have been attributed to reduction in particle size, increase in surface area and high surface basicity.

A physicochemical research of the processes of phase composition formation in the materials of the Dy-Sn-O system was performed. Phase composition was taking place in the course of thermal treatment of dysprosium (III) and tin (IV) codeposition products. These were codeposited from nitrate solutions at pH 7, and 25% ammonia water was used as the precipitant. Using thermal and X-ray diffraction analysis, it was found that in the above system at 90 wt. % of Dy2O3 and 10 wt. % of SnO2, when the precursors were heated above 600°C there are no solid solutions. In the meanwhile, at temperatures below 1000°C there is only one phase, Dy2O3. At temperatures above 1000°C, the system becomes bi-phase and includes Dy2O3 and Dy2Sn2O7.

Nano-crystalline Ce1-xDyxO2-δ (x = 0.1-0.5) materials were prepared using the low temperature citrate auto-ignition method. The Rietveld analysis of the XRD data confirmed the single phase cubic fluorite structure. The particle sizes of the sintered samples are in nano range and lattice parameter increases with Dy concentration. Polydispersed and agglomerated particles are observed by SEM. The EDAX spectra show good stoichiometry of the different atoms in the samples. The conductivity is found to have both grain and grain boundary contribution and shows highest value at x= 0.2. The frequency dependence of dielectric permittivity has been analyzed using Havrilliak-Negami formalism. The variation in different electrical properties has been explained by formation defect associates and their interaction with charge carriers.

Undoped ZnO and rare earth elements (Ce, Dy and Er with 2 at. %) doped nanoparticles were synthesized by wet chemical co-precipitation method at 90°C with Polyvinylpyrrolidone (PVP) as capping agent. The structural, morphological, compositional and photoluminescence studies were performed with X-ray diffraction (XRD), Transmission electron microscopy (TEM), Energy dispersive spectroscopy (EDS), FTIR spectroscopy and Photoluminescence (PL) respectively. XRD results revealed hexagonal wurtzite structure with average particle size around 18 nm - 14 nm and are compatible with TEM results. EDS confirm the incorporation of Ce, Dy and Er elements into the host ZnO matrix and is validated by FTIR analysis. PL studies showed a broad intensive emission peak at 558 nm in all the samples. The intensity for Er- doped ZnO found maximum with additional Er shoulder peaks at 516nm and 538 nm. No Ce, Dy emission centers were found in spectra.

Using first principles density functional theory (DFT) calculations within GGA and GGA+U approximations we studied both ferromagnetic (FM) and antiferromagnetic (AFM) phases of zircon type RCrO4 (R= Dy, Ho, Gd) oxides. We estimated and compared the 3d-4f exchange interaction strengths J between the nearest neighbor R3+ and Cr5+ ions for R=Dy, Gd. Our results predict that DyCrO4, GdCrO4 and HoCrO4 have ferromagnetic ground state which is consistent with experimental observations.

Nanorods of CaSO4: Dy having diameter 20 nm and length 200 nm have been synthesized by the chemical coprecipitation method. These samples were irradiated with gamma radiation for the dose varying from 0.1 Gy to 50 kGy and their TL characteristics have been studied. TL dose response shows a linear behavior up to 5 kGy and further saturates with increase in the dose. A Computerized Glow Curve Deconvolution (CGCD) program was used for the analysis of TL glow curves. Trapping parameters for various peaks have been calculated by using CGCD program.

Nanostructural, multifunctional, multiferroic materials possessing strong magnetoelectric coupling, open exciting multitudinous ways for designing future spintronic and data storage device applications. Pure and 15% Dy-doped BiFeO3 multiferroic nanoparticles (NPs) with size 24 and 20 nm respectively have been synthesized by sol-gel method. The effect of Dy-doping and size of synthesized nanoparticles on structural, electrical, magnetic and magnetodielectric properties have been investigated. The magnetoelectric coupling (ME) in synthesized NPs have been estimated by measuring magnetodielectric. The possible origin of enhancement in above said properties have been explained on the basis of dopant, phase purity, structural transformation and the small size synthesized NPs.