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[en] The electronic structures (especially 4f states) of hexagonal and tetragonal erbium silicides are investigated within density functional theory. Contrary to previous theoretical studies on these compounds, Er 4f electrons are treated as valence state electrons, explicitly taking into account the on-site Coulomb interactions. Total energy calculations show that the relaxed hexagonal ErSi1.7 is more stable than the tetragonal structure, consistently with related experimental observations. The calculated total density of states of the hexagonal ErSi1.7 agrees well with the experimental valence-band spectrum in a wide energy range from 0 to 12 eV below the Fermi level. In addition, our study indicates that the occupied 4f states in erbium silicides can also locate in the energy range of 0 - 4.0 eV below the Fermi energy, much different from the prediction of the previously adopted Er ion model. (authors)
[en] In this article, we present the investigations of temperature dependent luminescence for the Ag0.05Ga0.05Ge0.95S2-Er2S3 glass system. The possibility to use temperature dependences of the photoluminescence of synthesized glasses for thermo sensors is considered. It is shown that logarithm of ratio of the integrated photoluminescence intensities for 980 and 600 nm (ln (I980/I660)) emission bands possess excellent linear dependence of temperature. At the same time, the nonlinear optical effects of two-photon absorption show substantial divergence from the sublinear dependences. These phenomena provide an opportunity to utilize Ag0.05Ga0.05Ge0.95S2-Er2S3 glasses for the fabrication of highly sensitive temperature sensor devices.
[en] Physical properties of a series of homologous RE-B-C(N) B12 cluster compounds REB17CN, REB22C2N, and REB28.5C4 (RE=Er,Ho) were investigated. The structures of the compounds are layer-like along the c-axis, with rare earth and B6 octahedral layers separated by B12 icosahedral and C-B-C chain layers whose number increases successively from two B12 layers for the REB17CN compound to four for the REB28.5C4 compound. The rare earth atoms are configured in two triangular flat layers which are stacked on top of one another in AB stacking where the nearest-neighbor rare earth directions are the three atoms forming a triangle in the adjacent layer. The series of homologous compounds exhibit a spin glass transition with Tf shifting in correspondence with variations of the basal plane lattice constants, consistent with the magnetic interaction being effective in the basal planes. The isothermal remanent magnetization shows a stretched exponential decay Im(t)∝ exp[-Ct-(1-n)]. Exponents determined for the different homologous compounds were scaled as a function of Tr=T/Tf and found to follow the empirical dependency determined for typical spin glasses. It is indicated that a mixture of disorder originating from the partial occupancy of the rare earth sites and frustration of interactions due to the unique configuration is responsible for the manifestation of spin glass transitions in these homologous systems
[en] This patent describes a burnable absorber coated nuclear fuel. It comprises a nuclear fuel substrate containing a fissionable material; and an outer burnable absorber coating applied on an outer surface of the substrate; the outer absorber coating being composed of an inner layer of a boron-bearing material except for erbium boride and an outer layer of an erbium material
[en] A comparative analysis of intermediate mass fragments (IMFs) and light particles (LPs) [equivalently, evaporation residues (ERs)] in the decay of 26,27,28,29Al⁎ has been carried out for reactions and at the energy range , within dynamical cluster decay model (DCM) of collective clusterisation approach. We find that, for IMFs having , the range of mass minima are , , and , respectively. With increase in the mass of compound nuclei, becomes more prominent as compared to its neighboring fragments which is also observed in the experimental data. The LPs cross sections () in the decay of 26-29Al⁎ are also estimated. We find that the value of of LPs for 26,27Al⁎ is less as compared to that for 28,29Al⁎, contrary to the value of ∑P. Eventually, the cross sections for LPs are having higher contribution in the decay of 28,29Al⁎ in agreement with the experimental data. As expected for light mass nuclei, the for 26,27Al⁎ find better comparison with experimental data for spherical considerations rather than deformations. We also conform Bohr's hypothesis via the entrance channel independence for compound nucleus 28Al⁎ formed through and channels at an excitation energy , by having a unique choice of neck length parameter ΔR for both the reactions.
[en] Thermal desorption analysis is used to characterize the outgassing properties of both vacuum envelope materials and the hydrided sources and targets in neutron generators employing erbium deuteride films and erbium tritide target