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The 92Mo(n,α)89Zr, 97Mo(n,p)97Nb, 148Nd(n,2n)147Nd and 146Nd(n,p)146Pr reaction cross sections with the neutron of energy of 14.54 ± 0.24 MeV have been measured by using the method of activation and off-line γ-ray spectrometry. The neutron was generated from the D-T reaction at the PURNIMA neutron generator of BARC. The 197Au(n,2n)196Au monitor reaction was used for the estimation of neutron flux. The covariance analysis for the uncertainties of the cross sections has been carried out by considering the partial uncertainties of different attributes. The present data have been compared with the literature data, evaluated data and theoretically calculated values from TALYS-1.9 code.

The 115In(n,2n)114mIn and 197Au(n,2n)196Au reaction cross sections have been measured relative to the 27Al(n,α)24Na monitor reaction at the two different incident neutron energies of 13.520 ± 0.005 MeV and 14.54 ± 0.24 MeV. The neutrons from the D-T fusion reaction at the Purnima neutron generator were used for activation followed by off-line γ-ray spectrometry. The uncertainty propagation and correlation of measured reaction cross sections were estimated using covariance analysis through considering the partial uncertainties in different attributes. The measured reaction cross sections from the present work have been compared with the literature data from EXFOR compilation, ENDF data of various libraries and theoretically calculated values from the TALYS-1.9 code.

The (n,2n) reaction cross sections of cerium isotopes have been experimentally measured at the neutron energy of 13.50 ± 0.15 MeV by using the method of activation and off-line γ-ray spectroscopy. The neutron energy was obtained from the D-T reaction using the Purnima Neutron Generator at BARC. The natCe sample was irradiated along with the gold and indium monitor foils. The cross sections of 140Ce(n,2n)139Ce and 142Ce(n,2n)141Ce reactions were measured by using both the gold and indium as a monitor and then collapsed to get the best values of reactions cross sections. The uncertainties in the measured cross sections of 140Ce(n,2n)139Ce and 142Ce(n,2n)141Ce reactions were determined using covariance analysis by considering uncertainties in various attributes. The measured values from the present work were compared with the literature data based on EXFOR compilation, evaluated data from different libraries and theoretically calculated values from TALYS-1.95 and EMPIRE-3.2.

Cerium (Ce3+)-substituted cobalt–nickel (Co–Ni) ferrite nanostructures of spinel cubic phase with space group Fd$$\bar{3}$$m had been successfully engineered by solution combustion route. The effect of Ce3+ substitution on the structural, morphological, dielectric, and impedance spectroscopic investigations are probed by using X-ray diffraction (XRD), scanning electron microscope (SEM), and impedance analysis, respectively. Rietveld refinement of XRD data reveal that samples exhibit well-crystalline nature with single phase. The microstructural realm with various Ce3+ doping levels has been identified from SEM micrographs. The replacement of Fe3+ by Ce3+ cations has been confirmed by using energy-dispersive analysis of the ferrite samples. The dielectric constant (e′), dielectric loss (tanδ), ac conductivity (σac), and impedance (Z′ and Z″) at room temperature is investigated as a function of frequency, respectively. The variation of dielectric properties e′, tanδ, σac with frequency are explained by Maxwell–Wagner type of interfacial polarization and the hopping of charge between Fe2+ and Fe3+ as well as the dopant ions at B-sites. The decrease in dielectric constant and dielectric loss tangent with frequency follows the phenomenon of Debye’s relaxation. The enhancement in AC conductivity with frequency is proportional to Ce3+ concentration which follows Jonscher law. The complex impedance plots (Z′ vs. Z″) allows to determine the contribution for conductivity either from grain or grain boundary. Complex electric modulus plot (M′ vs. M″) provides the validation to the result drawn from the complex impedance plots. The results indicate the existence of non-Debye type of relaxation in these ferrites. Impedance spectroscopy allows the ferrite materials to estimate electrical properties which arise due to hopping and relaxation phenomena.

Nanoparticles of Co0.5Ni0.5Fe2−xCexO4 (where x = 0.0, 0.01, 0.015 and 0.02) ferrites are prepared by the modified solution combustion method using a mixture of fuels and are characterized to understand their structural, microstructural and magnetic properties. The X-ray diffraction is used to confirm the formation of a single-phase cubic spinel structure. The average crystallite sizes are calculated using the Scherrer formula and are found to be less than 50 nm. The microstructural features are obtained by the scanning electron microscopy, and the compositional analysis is done by using the energy-dispersive spectroscopy. The transmission electron microscopy (TEM) investigations show that the synthesized ferrites are made up of very fine spherical nanoparticles. The influence of a rare-earth element (Ce3+) on the magnetic properties of the samples was studied using the Mossbauer spectroscopy. The Mossbauer spectroscopy reveals the formation of broadened Zeeman lines and quadrupole-split lines and the presence of the Fe3+ charge state at B sites in the samples. The quadrupole splitting shows that the orientation of the magnetic hyperfine field with respect to the principle axes of the electric field gradient was random. The magnetic hyperfine field values indicate that the A sites have more A-O-B superexchange interactions than the B sites. The coexistence of magnetic sextet and a doublet component on the room-temperature spectra suggests superparamagnetic properties of the nanoparticles. The low-temperature (15 K) Mossbauer spectroscopy explores the paramagnetic relaxation in the nanoparticles. The area under the sextet refers to Fe3+ concentrations in the tetrahedral and octahedral sites of the ferrite. This study confirms that the Ce3+ substitution of Fe3+ only for octahedron sites causes the decrease in Fe-O-Fe arrangement. The effect of Ce3+ doping on the magnetic properties of Co0.5Ni0.5Fe2O4 is examined from the vibrating sample magnetometry (VSM) spectra. Saturation magnetization values are decreased initially and then increased, as result of Ce3+ doping. This can be explained by Neel’s two-sub-lattice model. Further, the value of coercivity is found to be increasing with increasing Ce3+ concentration. The obtained results of M-H loop with improved coercivity (from 851 to 1039 Oe) by Ce3+ doping of Co0.5Ni0.5Fe2O4 demonstrate the usefulness for permanent magnet applications.

Nano size Mn0.4Zn0.6SmxFe2−xO4 (x = 0.00, 0.01, 0.02, 0.03, 0.04, and 0.05) ferrites were prepared by solution combustion method. The structural and magnetic properties of samples were characterised by X-ray diffractometer, Fourier transform infrared spectrometer, transmission electron micrographs and magnetic properties at room temperature. The X-ray diffraction patterns and two prominent absorption bands in the frequency range 375–589 cm−1 confirmed the single phase with spinel cubic structure. The average nano crystallite sizes were in best agreements with transmission electron microscope images. Magnetic studies revealed the narrow hysteresis loops of ferrimagnetic nature at room temperature. The values of saturation magnetization (M s ), remanence magnetization (M r ), coercivity (H c ), remanence ratio (M r /M s ), magneton number, anisotropy constant and Yaffet–Kittle angle decreased with the increase in Sm3+ ion concentration was attributed to relative number of ferric ions on the tetrahedral sites diminished and reduced the Sm–Fe interaction.

A comparative study of spherical and rod-like nanocrystalline GdO:Eu (GdEuO) red phosphors prepared by solution combustion and hydrothermal methods have been reported. Powder X-ray diffraction (PXRD) results confirm the as-formed product in combustion method showing mixed phase of monoclinic and cubic of GdO:Eu. Upon calcinations at 800C for 3 h, dominant cubic phase was achieved. The as-formed precursor hydrothermal product shows hexagonal Gd(OH):Eu phase and it converts to pure cubic phase of GdO:Eu on calcination at 600C for 3 h. TEM micrographs of hydrothermally prepared cubic GdO:Eu phase shows nanorods with a diameter of 15 nm and length varying from 50 to 150 nm, whereas combustion product shows the particles to be of irregular shape, with different sizes in the range 50-250 nm. Dominant red emission (612 nm) was observed in cubic GdO:Eu which has been assigned to transition. However, in hexagonal Gd(OH):Eu, emission peaks at 614 and 621 nm were observed. The strong red emission of cubic GdO:Eu nanophosphors by hydrothermal method are promising for high performance display materials. The variation in optical energy bandgap () was noticed in as-formed and heat treated systems in both the techniques. This is due to more ordered structure in heat treated samples and reduction in structural defects.

An attempt has been made to estimate the effective atomic number, electron density (0.001 to 105 MeV) and kerma (0.001 to 20 MeV) of gamma radiation for a wide range of oxides of lanthanides using mass attenuation coefficient from WinXCom and mass energy absorption coefficient from Hubbell and Seltzer. The values of these parameters have been found to change with energy for different oxides of lanthanides. The lanthanide oxides find remarkable applications in the field of medicine, biology, nuclear engineering and space technology. Nano-oxides of lanthanide find applications in display and lighting industry.

Geometric progression fitting method has been used to compute energy absorption build-up factor of teeth [enamel outer surface, enamel middle, enamel dentin junction towards enamel, enamel dentin junction towards dentin, dentin middle and dentin inner surface] for wide energy range (0.015–15 MeV) up to the penetration depth of 40 mean free path. The dependence of energy absorption build-up factor on incident photon energy, penetration depth, electron density and effective atomic number has also been studied. The energy absorption build-up factors increases with the penetration depth and electron density of teeth. So that the degree of violation of Lambert–Beer (I = I0e−μt) law is less for least penetration depth and electron density. The energy absorption build-up factors for different regions of teeth are not same hence the energy absorbed by the different regions of teeth is not uniform which depends on the composition of the medium. The relative dose of gamma in different regions of teeth is also estimated. Dosimetric implication of energy absorption build-up factor in teeth has also been discussed. The estimated absorption build up factors in different regions of teeth may be useful in the electron spin resonance dosimetry.

Cobalt ferrite (CoxFe3−xO4) is prepared in powder form by thermal decomposition of iron and cobalt salts and is analysed by X-ray diffraction and Mossbauer spectroscopic techniques. The variation of Mossbauer parameters, lattice parameters and crystallite size of the products formed with variation in the composition of Fe and Co ratios are studied. The studies confirm the formation of nano-size cobalt ferrite particles with defect structure and it is found to be maximum for the Fe : Co = 60 : 40 ratio of the initial precursor oxides.

External bremsstrahlung produced in thick targets of Al, Cu, Mo, Cd and Pb by the beta-particles of147Pm has been investigated using a (4.55×5.08) cm2 NaI(Tl) scintillator. The measured spectra after unfolding have been compared with the Bethe-Heitler, Elwert-corrected Bethe-Heitler, Morgan-corrected Bethe-Heitler and Tseng and Pratt theories. The experimental spectra agree fairly well with the EBH theory up to about 120 keV and deviate positively thereafter from all the theories.