3d9 4s Research Articles

Thermoluminescence from Cu Doped Lithium Tetraborate Irradiated with X-ray and γ Using 137Cs Radioactive Source

Lithium tetraborate (Li2B4O7) pellets prepared by using water/solution assisted method were synthesized and characterized. Copper was used as doping material in order to enhance the Li2B4O7 thermoluminescent properties. For synthesis heating temperature parameters were defined at 750 °C for 2 hr, followed by 150 °C for another 2 hr. The materials were produced at five different Cu concentrations: 0.02, 0.04, 0.06, 0.08, and 0.1 wt%. The luminescent and morphological characterizations were performed by X-ray diffraction (XRD), Scanning electron microscope (SEM), Photoluminescence (PL), and Ultraviolet-visible spectroscopy (UV-Vis). XRD and SEM analysis of intrinsic and doped materials confirmed the obtained Li2B4O7 structure and show its morphology. XRD patterns of the Li2B4O7 matched a tetragonal crystal structure. Crystals of Li2B4O7 of an average size of 50 nm were obtained. The presence of the copper dopant was confirmed in crystals of Li2B4O7:Cu by SEM-EDS (energy dispersive spectroscopy X-ray). The emission spectrum of Cu doped Li2B4O7 showed a prominent peak at 367 nm, while the main UV-Vis absorption was observed from 240 nm to 300 nm due to Cu+ ion 3d10 → 3d9 4s transitions. The thermoluminescent (TL) response was studied for both γ radiation and X-ray. A 661.7 keV γ radiation using a 137Cs source at doses of 50, 100, 200, 300, 400 and 500 mGy was applied to Li2B4O7:Cu (0.1 wt%) pellets. An X-ray source was used at doses of 600, 800 and 1000 mGy to irradiate pellets of Li2B4O7:Cu (0.02, 0.04, 0.06, 0.08 and 0.1 wt%). A linear TL response was observed for both X-ray and γ radiation. The kinetic parameters were calculated using the peak shape method for the Li2B4O7:Cu (0.1 wt%).

Lifetime measurements of the 3d 94s(1 D) 4p configuration of Cu I

The radiative lifetimes of the levels in the 3d94s(1D)4p configuration of Cu I are measured. The levels are excited from the metastable 3d94s22D3/2,5/2 levels. The metastable Cu atoms are generated in a pulsed hollow cathode discharge. The levels investigated are populated with a 35-ps laser pulse at wavelengths around 220 nm. The laser induced fluorescence signal is detected. The lifetime of the 3d94s(3D)4p4D1/2 level is also determined by direct excitation from the ground state. A comparison with calculated literature values is given.

Analysis of autoionizing Rydberg series Cu I 3d 9 4snl with the multichannel quantum defect theory

Using atomic beam technique, a combination of collisional and laser excitation, and photoion detection, autoionizing Cu I states in the region of the ionization limits Cu II 3d9 4s(3,1D) were investigated. In spite of the complicated structure of the signals due to the four different ionization limits3D3,3D2,3D1 and1D2 and the large number of possible (LSJ)-states, which can be reached by this experimental technique, the majority of the signals could be attributed to definite Rydberg series 3d9 4s(3D3,3D2,3D1,1D2)nl (LSJ). Perturbations were analyzed by the three- and four-channel quantum defect theory and by Hartree-Fock calculations. General formulas for the calculation of the photoionization cross section by the four-channel quantum defect theory in the case of two closed and two open channels are given.

Optically detected magnetic resonance of the luminescent state in NaF:Cu +

Optically detected electron paramagnetic resonance (OD-EPR) Spectra at 22.9, 75.0, and 94.9 GHz of the luminescent state of Cu + ions in NaF are reported. The EPR spectra do not support the current T lg( 3E g, 3d 94s) “atomic” assignment of the luminescent state, but point to a paramagnetic species with g values in the range of 2.0–2.5, a very small or no zero-field splitting and a spin density in the Cu 4s oribtal lower than 0.04.

Investigation of autoionizing CuI-states in the region of the second ionization limit CuII 3d 94s

The combination of collisional and laser excitation was used for the investigation of autoionizing CuI states in the region of the second ionization limit CuII 3d9 4s at 85000–95000 cm−1. The analysis of the complicated signal structure was concentrated on the first measurement of CuI 3d9 4p2 levels. The experimental results are compared with Hartree-Fock calculations of the energy values and level widths of the autoionization resonances.

Lifetimes and perturbations of the 3d9 4s(3D) 4p structure in the spectrum of copper I

Natural radiative lifetimes have been measured of the2P,2D,2F and4D5/2 terms in the 3 d9 4s(3D) 4p structure of copper I. A pulsed hollow cathode was used to generate 3d9 4s22D metastable atoms. From these metastable levels the states investigated were populated by a pulsed dye laser pumped by a Nd:YAG laser. A comparison with theoretical and experimental literature values is given.

Lifetime measurements and stark mixing of autoionizing Cu I-states

Using a combination of collisional and laser excitation the lifetimes of 17 autoionizing Cu I states in the configurations 3d 9 4s 6s and 3d 9 4s4d were measured. The lifetimes are in the range of 1–50 ps and depend strongly on the coupling properties, the mixing with different configurations, and the radial integrals of the discrete with the continuum states. For the level 3d 9 4s 4d 4 S 3/2 the influence of an electric field via Stark mixing of 3d 9 4s 5p 4 P 1/2 on the autoionizing rate was investigated. The experimental values are compared with theoretical results which follow from ab initio calculations for the transition probabilities and least square fit values deduced from the experimental positions. Good agreement is found only for theJ=3/2 levels of both configurations 3d 9 4s 4d and 3d 9 4s 6s.

On a new hydrogenated Cu (I) nasicon-type phosphate H 0.5Cu I0.5Zr 2(PO 4) 3

Absorption of hydrogen in Cu II 0.5Zr 2(PO 4) 3 gives rise to a new Cu (I) Nasicon-type derived phosphate H 0.5Cu I 0.5Zr 2(PO 4) 3 as the result of an intercalation process. Various physical properties have been investigated. The copper (I) luminescence has been explained on hand of the position of the lowest levels of the Cu (I) 3d 94s 1 electronic configuration within the forbidden gap.

Electron affinities of states of Sc and Cu

With this work, we begin our treatment of the transition metal electron affinities. A procedure, REDUCE, for reducing the number of parental couplings per configuration present in the first order wave function from as many as 100 to only a few is introduced. Progress toward a comprehensive relativistic-correlation theory is discussed. Several states in Sc− were examined but none were found to be bound. Two new bound states were obtained for Cu−: 3d9 4s 4p25D and 3d8 4s 4P37F0, with electron affinities 0.109 and 1.052 eV, respectively.

Theoretical description of the low-lying excited states of CuCl

The low-lying excited states of CuCl have been investigated theoretically in the Hartree-Fock approximation. Spin-orbit interactions have been included semi-empirically using an atoms-in-molecules technique. All six excited states that were previously characterized experimentally are found to arise from fine structure sublevels of the Cu +(3d 94s 1,3D)Cl −(3p 6 1S) configuration.

Crossed-second-order specific-mass isotope shift in the Nickel atom

The crossed-second-order corrections to the specific mass shifts of the lowest terms of the two lowest configurations of the Nickel atom are evaluated ab initio in the Multiconfigurational Hartree-Fock scheme. The excitations towards the nf(l=3) empty subshells play the major role. If the contributions obtained are added to the Hartree-Fock values, the discrepancy between experiment and theory for the 3d8 4s2−3d9 4s (virtual) transition is only reduced by one third. As concerns the differences between the specific shifts of the five Russell-Saunders terms of 3d8 4s2, the crossed-second-order contributions are predicted to be practically as large as the Hartree-Fock values, which makes the total definitely measurable.

A matrix-induced change in the electronic ground state of nickel atoms isolated in rare gases

Comparison of the absorption spectra for matrix-isolated Ni atoms with gas-phase data reveals that the electronic ground-state configuration of the isolated atom can be changed by the matrix. While Ni in Ne has the same configuration as in the gas phase, namely 3d 84s 2 we find in Ar, Kr, and Xe the 3d 94s 1 configuration to be the ground state. The matrix-induced changes is explained by the repulsive matrix-dopant interaction, which is sufficiently lowered in the 3d 94s 1 configuration to overcompensate for the energy difference of 205 cm −1 by which the 3d 94s 1 level lies above the 3d 84s 2 in the free atom.

Sixth and seventh spectra of arsenic: As vi and As vii

The spectrum of arsenic was photographed in the regions 1200–500 A and 300–100 A on a 6.65 normal-incidence and a 10.7 m grazing- incidence spectrograph, respectively. The source used was a triggered spark. These measurements enabled us to revise and extend the earlier analysis of As vi. In this spectrum we established all levels of the 3d10, 3d9 4s, 3d9 4p, and 3d9 4d configurations except 3d9 4d1S0. In addition the identification of the 3PO1, lPO1, and 3D°1 level’s in the 3d9 5p, 3d9 4f, and 3d9 5f configurations has led to a new value of the ionization limit of As vi: 974 000 cm−1 (120.7 eV). In As vii the earlier analysis of the 3d9−3d8 4p transitions has been revised and extended and the 3p5 3d10 2P levels were located. The parametric level fitting calculations support the analysis. 109 lines have been classified in As vi and 47 lines in As vii.

A theoretical investigation of the ground and core hole states of linear and bent NiCO; a prototype for CO adsorbed on nickel

Non-empirical LCAO MO SCF calculations within the Hartree-Fock formalism have been performed on linear and bent conformations of NiCO, for both the states arising from the 3d 94s 1 and 3d 10 electronic configurations of Ni, for ground and core ionized species. Binding and relaxation energies are computed for the nickel atom, the free ligand (CO) and the absorbed species (NiCO). Comparison with available experimental data reveals good agreement for the shifts in core binding energies for the bent, 3d 94s 1 NiCO system. The main contribution to these binding energy shifts is found to be due to relaxation effects, which may be rationalized in terms of atomic population and bond overlap changes accompanying core ionization.

Calculations of Znii 3d94s5s and Agi 4d95s6s, and Some New Levels in these Spectra.

Results of intermediate-coupling calculations are given for Zn ii 3d 94s5s and Ag i 4d 95s6s. A [(4d 9)J i, (5s6s)J ii]J coupling scheme is appropriate for the latter. New 3d 94s(3D)5s 2D2½ and 3d 94s(1D)5s 2D2½ levels were found in Zn ii, and a few other additions and revisions are given for the analysis. The combinations of the new levels 3d 9(2D)4s4p(3P°) in Zn ii and 4d 9(2D)5s5p(3P°) in Ag i are also listed.

Bestimmung der Lebensdauer des 3d 9 4s 4p 4 P 3/2-Terms im Cu I-Spektrum mit optischer Doppelresonanz

The lifetime of the 3d9 4s 4p4P3/2 state of Cu has been determined with optical double resonance by observation of radiofrequency transitions ΔF=0, Δm F =±1 between hfs-Zeeman levels of the stable odd isotopes. The result is τ(3d9 4s 4p4P3/2, Cu)=3.18(16)·10−7 sec.