Progress towards blue emitting MgO-ZnO-Ga2O3 nanocomposites synthesized by bio mediated route

MgO-ZnO-Ga2O3 nanocomposites are synthesized by solution combustion method using Aloe Vera gel as a reducing agent to increase the efficiency of blue emission. The appearance of Bragg reflections corresponding to MgO, ZnO and Ga2O3 clearly indicates the formation of nanocomposites. The surface morphology consists irregular shape and sized NPs. The Energy dispersive X-ray analysis confirms the purity of the sample. The band energy gap was tuned to 3.1 eV. The Photoluminescence excitation and emission spectra was discussed and compared it with emission spectra of individual oxides as well as with other reported blue emitted nanophosphors. Further, the chromaticity coordinates and Color correlated temperature coordinates clearly confirms their warm blue emission. Further, the powder dusting method was employed to collect the latent fingerprints on the pores and non-pores surfaces. The synthesized MgO-ZnO-Ga2O3 nanocomposites exhibits well-resolved ridge patterns that can be used to identify latent finger prints with clarity. From all these results, the present synthesized MgO-ZnO-Ga2O3 nanocomposite might find an application in display technology as a blue nanophosphor material and for latent finger print detection in crime investigation.

X-ray/gamma radiation shielding properties of zinc ferrite nanoparticles synthesised via solution combustion method

Zinc ferrite (ZnFe2O4) nanoparticles were synthesised via solution combustion method using urea as a fuel. The synthesised samples were characterised with various techniques. The cubic structure with Fd-3 m space group is confirmed by Powder X-ray Diffraction and Bragg's reflection. The crystallite size estimated from Scherrer's method was found to be 40 nm. The agglomerated irregular shape and sized surface morphology was confirmed by Scanning Electron Microscopy image. The direct energy band gap determined from Wood and Tauc's relation was found to be 5.25 eV. Using a NaI (Tl) detector and multi-channel analyser, the described sample was examined for X-ray and gamma ray shielding characteristics in the energy range of 0.081-1.332 MeV. The measured shielding values are in good agreement with the theory, however below 356 keV, there is a little variation of up to 10%. The current work offers up new possibilities for using this simple, affordable, effective and low temperature approach to create nanomaterials for X-ray and gamma ray shielding.

Synthesis and characterization of Ag-doped cerium oxide nanoparticles for electromagnetic radiation shielding

In the current study, CeO2: Ag (0 and 11 mol) nanoparticles (NPs) were synthesized by solution combustion method using Aloevera extract as reducing agent. As-obtained NPs were characterized by standard techniques. Bragg's reflections confirm the formation of a single-phase cubic structure of CeO2:Ag NPs. Crystalline size is calculated using both the W-H plot and Scherrer's equation. Crystallite size found to decrease with increase in the dopant concentration. EDAX pattern confirmed the presence of Ce, O and Ag. Direct energy band calculated using Wood and Tauc's was found to be in the range of 2.9-2.2 eV for 0 and 11 mol, respectively. Fourier transformation infrared spectroscopy (FTIR) analysis confirmed the presence of the functional groups. Total shielding efficiency (SET) will give the best representation of EMI shielding properties. SET values calculated for a wide range of wavelengths are found to be as follows: near infrared (1.65 × 102 dB), mid infrared (9.78 × 101 dB) and far infrared (6.32 × 101 dB), followed by microwave region (MW) (6.46 × 101 dB), ultra-high frequency (UHF) (7.31 × 101 dB), very high frequency (VHF) (8.27 × 101 dB), high frequency (HF) (9.26 × 101 dB), medium frequency (MF) (1.02 × 102 dB), low frequency (LW) (1.12 × 102 dB), very low frequency (VLF) (1.22 × 102 dB), ultra-low frequency (ULF) (1.42 × 102 dB) and extremely low frequency (ELF) (1.52 × 102 dB). SET values of CeO2:Ag NPs are compared with other traditional materials and nanocomposites and found to be potential use in EMI shielding applications.

Synthesis and characterisation of Zn-doped cerium oxide nanoparticles for electromagnetic radiation shielding

CeO2-NPs (nanoparticles) exhibit a variety of properties, which have prompted researchers to explore various applications, such as gas sensing, biomedical, Electromagnetic Interference (EMI) shielding, etc. Zn-doped CeO2-NPs with concentrations ranging from 7 to 11 mol were synthesised using Aloe vera extract as a reducing agent by the solution combustion method. As obtained, NPs were characterised by standard techniques. Braggs reflections confirm the formation of a single-phase cubic structure of CeO2Zn NPs. Crystalline size is calculated using both the W-H plot and the Scherrer equation, which were found to be 12 and 9 nm, respectively. The Energy-dispersive X-ray analysis (EDAX) pattern confirmed the presence of Ce, O and Zn. The direct energy band values are found to be decreasing from 3 to 2.87 eV with an increase in the doping concentration of Zn from 7 to 11 mol. Total shielding efficiency (SET) will give the best representation of shielding properties. The SEt values of CeO2Zn NPs are compared to those of other conventional materials and NP materials, finding significant applications in EMI shielding.

Synthesis and characterization of calcium-iron-chromium nanocomposites for electromagnetic radiation shielding application

Over a century, shielding harmful electromagnetic radiations (EMR) and finding a suitable material, which can replace lead has become the major interest of researchers in this field. Herein, calcium-iron-chromium oxide nanocomposites with the different atomic ratios are synthesized using the solution combustion method. The as-obtained nanoparticles (NPs) are subjected to several structural and surface characteristics such as powder X-ray diffraction, scanning electron microscopy, elemental diffraction X-ray analysis, Fourier Transform Infrared Spectroscopy and UV-visible spectroscopy analysis were performed to confirm the successful synthesis. Furthermore, the EMR shielding of as-procured NPs is investigated and observed that the obtained NPs show good shielding properties.

An innovative approach for estimating energy absorption buildup factors (EABF) with HVL and TVL

The current study proposes an empirical formula for absorption buildup factors as a function of target thickness. The present formula produces absorption buildup factors of compounds and mixtures with simple inputs of linear attenuation coefficient (μ), tenth value layer (TVL) and half value layer (HVL) of interacting target for the atomic number region 29 < Z < 92 for the energies 0.2 MeV < E < 1.5 MeV. This method is used to compute the energy absorption buildup factors using HVL and TVL.

Heavy particle radioactivity of superheavy nuclei

We investigated different decay modes such as heavy particle radioactivity (HPR), spontaneous fission (SF), alpha decay and beta-decay in superheavy (SH) region 104 ≤ Z ≤ 126. In HPR, different emissions from Zmin = 28 to maximum heavy particle (HP) emission up to Zmax = Z - 82 were considered. In the evaluation of Q-values, mass excess Weizsäcker-Skyrme 4+radial basis function (WS4+RBF) values were taken into account. The half-lives of cluster decay determined using modified generalised liquid drop model (MGLDM) and Coulomb and proximity potential model (CPPM) were in close agreement with the experimental results. The MGLDM produce less deviation compared with CPPM. The role of asymmetry effect, relative neutron excess, pairing effect and Coulomb effect on half-lives were studied. A band of neutron numbers from 193 to 200 shows extra stability against HPR. The HPR of 86Kr, 94Zr, 91Y and 96Mo is observed in the superheavy elements Z = 118, 122-124 and 126. The dominant decay mode identified is compared with SF, alpha and beta± decay, the majority of decay chains end with the lead nuclei, which is also evident in supernova and galaxy spectrum. This study could be useful in nuclear astrophysics.

Neem leaves mediated synthesis of CeO2 nanoparticles for X/gamma ray absorption applications

Cerium oxide (CeO2) nanoparticles (NPs) exhibit a variety of properties, which have prompted researchers to explore CeO2 NPs in various applications such as biomedical, electrochemical, gas sensing and display applications. CeO2 NPs capabilities were impacted by the type of synthesis mechanism. CeO2 NPs were synthesized by solution combustion method using neem leaves extract as a reducing agent. The synthesized sample is characterized with different techniques. The Bragg reflections confirm the formation of cubic spinel structure. The surface morphology consists of agglomerated NPs. The direct energy band gap was found to be 2.9 eV. X-ray radiation absorption properties were studied within 1 keV-100GeV range. The results indicate that CeO2 NPs found to be potential in radiation applications.

Gamma and X-Ray Shielding Properties of Various Types of Steels

We have calculated the gamma and X-ray shielding parameters such as mass attenuation coefficient, half value layer (HVL), tenth value layer (TVL), specific gamma ray constant, effective atomic number, and buildup factors in various steels. By studying these X-ray and gamma interaction parameters, we have selected the best steel which can be used for the X-ray and gamma shielding material. The steel type 20Mo-4 is having higher values of mass attenuation coefficient, specific gamma ray constant, effective atomic number, and buildup factor and smaller values of HVL and TVL. A detail analysis of X-ray/gamma interaction in the different steels reveals that the steel type (S15) 20Mo-4 is good absorption of both X-ray/gamma radiations.

Gamma, X-ray and neutron shielding parameters for the Al-based glassy alloys

The X-ray and gamma radiation shielding parameters (mass attenuation coefficient, mean free path, half value layer, tenth value layer, effective atomic numbers, electron density, exposure buildup factors, relative dose, dose rate and specific gamma ray constant) have been studied for the Al-based glassy alloys Al₈₆Y₇Ni₅Co₁Fe_0.5Pd_0.5, Al₈₅Y₈Ni₅Co₁Fe_0.5Pd_0.5, Al₈₄Y₉Ni₄Co_1.5Fe_0.5Pd₁, Al₈₀Y₁₃Ni₅Co₁Fe_0.5Pd_0.5, Al₇₀Y₂₃Ni₅Co₁Fe_0.5Pd_0.5 and Al₆₀Y₃₃Ni₅Co₁Fe_0.5Pd_0.5. For the same alloys, the neutron shielding parameters (coherent neutron scattering length, incoherent neutron scattering lengths, coherent neutron scattering cross section, incoherent neutron scattering cross sections, total neutron scattering cross section and neutron absorption cross sections) have also been explored. Al₆₀Y₃₃Ni₅Co₁Fe_0.5Pd_0.5 was found to be a good shielding material for the X-ray/gamma radiation, while Al₈₆Y₇Ni₅Co₁Fe_0.5Pd_0.5 is a good shielding material for neutrons.