Energy Levels Of Nd3 Research Articles

Factors affecting the antibacterial effects of Nd:YAG laser in vivo.

One of the main advantages of laser surgery is it's bactericidal effect which reduces the risk of postoperative infections. Several study designs have been set to investigate this effect. Aim of this study was to research if the bactericidal effect of laser tool was affected from several factors in vitro studies. To determinate and investigate the bactericidal effect of laser in an original model, alpha-hemolytic streptococcus, Bacterioides fragilis, Neisseria, Streptococcus salivarius, Staphylococcus aureus, and Candida albicans were prepared in 10(4), 10(6) and 10(8) inoculum and placed in Mueller-Hinton Broth which have five different proportions of sheep blood. Samples which exposed with various energy levels of Nd:YAG laser were spread on agar plates, and at the end of an incubation time the colonization counted comparatively. The lowest energy level without colonization was accepted as minimal bactericidal energy level. Highest minimum bactericidal energy level is used for alpha-hemolytic streptococcus and lowest values for neisseria. Bactericidal effect decreased on suspensions, of which population of microorganisms are high and hemoglobin concentration was high in the broth. These findings suggest that the Nd:YAG laser has a higher bactericidal effect when sheep blood is added to the media. Factors like population and type of bacteria in the irradiated suspension affect minimum bactericidal energy level.

Spectroscopic studies and dynamics of Nd 3+ ions in RbY 2Cl 7 single crystals. Part II. Crystal-field analysis

Crystal-field energy levels of Nd 3+ ions doped in the two slightly inequivalent sites of the RbY 2Cl 7 host crystal were assigned and fitted to the parameters of a semiempirical Hamiltonian representing the combined atomic and crystal-field interactions. Using the one-electron crystal-field formalism 151 levels of the Nd(1) site and 156 levels of the Nd(2) site were assigned with a r.m.s. deviation of 17.5 and 15.4 cm −1 , respectively. Including correlation crystal-field terms into the semiempirical Hamiltonian we could obtain an improvement of the r.m.s. deviation for the Nd(1) and Nd(2) site up to 11.4 and 10.3 cm −1 , respectively, as well as the elimination of major discrepancies between the calculated and observed energy levels within the anomalous 2 H(2) 11/2 and 2 F(2) 5/2 multiplets.

Optical absorption spectra and Judd-Ofelt analysis of Nd 3+ in certain chloroborate glasses

Optical absorption bands have been measured and assigned to transitions between the energy levels of Nd 3+. From the optical absorption measurements and using Judd-Ofelt theory, intensity parameters ( Ω 2, Ω 4, Ω 6 ) have been calculated. The agreement is good between the theoretical and experimental spectral intensities. The radiative transition probabilities ( A), radiative lifetimes ( T R), branching ratios (β) and integrated absorption crosssections (Σ) have also been theoretically estimated and reported for certain fluorescent levels.

Term isotope shift of high lying odd and even energy levels of Nd II

The isotope shifts of the odd and even parity energy levels of singly-ionised neodymium (Nd II) have been evaluated using the measurements carried out in more than 300 spectral lines of Nd II in the region 3290–5820 A. Term shift, ΔT (144Nd-150Nd), is being reported for 23 low even and 15 high lying even parity levels of Nd II. ΔT for a level of 4f36s6p configuration and 8 even levels between 36892 and 43212 cm-1 are being reported for the first time. ΔT values of 151 high lying odd parity levels are being reported and compared with some of the available earlier reported values. ΔT values of 47 odd parity levels are being reported for the first time, most of which are based on our isotope shift studies in UV region. The electronic configuration assignments to energy levels of Nd II by earlier workers are discussed on the basis of present ΔT values. Electronic configurations to some of the unclassified high lying odd levels have been suggested; the levels with ΔT (144–150) between 300mK and 380mK are assigned to 4f35d6s configuration whereas a level with ΔT value of 60mK to 4f46p configuration.

Photoacoustic Spectra of Complexes of Neodymium(III) with Glyceine and Alanine

Abstract The complexes of Nd(Gly)3Cl3.3H2O and Nd (Ala)3Cl3.3H2O were synthesized and the photoacoustic (PA) spectra in the 300 - 800 nm region of the complexes were reported. Their PA and absorption spectra were interpreted. Their PA relative intensities represented by intensity branching vectors and the perturbation of ligands on the energy levels of Nd3+ ion were discussed. The fluorescent properties of Nd(Gly)3Cl3.3H2O and the relaxation process models were also studied based on its PA and absorption spectra.

Photoacoustic spectra of Nd(TFA) 3 · 2H 2O and Nd(HFA) 3 · 2H 2O

A new synthesis of trisfluoroacetylactone (TFA) and hexafluoroacetylactone (HFA) Nd complexes: Nd(TFA) 3 · 2H 2O and Hd(HFA) 3 · 2H 2O is reported. The photoacoustic (PA) spectra in the 300–800 nm region of the compounds NdCl 3 · 6H 2O, Nd(TFA) 3 · 2H 2O and Nd(HFA) 3 · 2H 2O are reported. The PA absorption bands are assigned and their relative intensities represented by intensity branching vectors are calculated. The perturbation of the ligand on the energy levels of Nd 3+ ion is discussed and a model of the relaxation process of Nd(HFA) 3 · 2H 2O is proposed based on its PA and absorption spectra.

Comparative crystal free-ion energy level analysis of Nd 3+ (4f 3) ions in various oxygen co-ordinated systems

We have reanalysed the crystal free-ion energy levels of Nd 3+(4f 3) ions in various oxygen co-ordinated systems. The best crystal free-ion energy level data available in the literature for the Nd 3+-doped systems of about 20 crystal hosts, namely, A-Nd 2O 3, Y 2O 3, YGaO 3, NdAlO 3, GdAlO 3, LiNbO 3, LiYO 2, NdNO 3·6H 2O, Ca(NbO 3) 2, Nd(NO 3) 3(DMSO) 4, La 2Be 2O 5, YVO 4, PbMoO 4, KY(MoO 4) 2, KY(WO 4) 2, LiGd(MoO 4) 2, CaAl 4O 7, Y 3Al 5O 12, Y 3Ga 5O 12 and Gd 3Ga 5O 12, were reanalysed in terms of a uniform free-ion model Hamiltonian. The free-ion model Hamiltonian consists of 20 free-ion parameters that are related to various interactions. The overall crystal free-ion parametrization of the experimental energy level data is reasonably good. The effects of the crystal hosts on the empirical parameters are examined. The nephelauxetic (β) and bonding (σ) parameters which are helpful to establish the trends of covalent or ionic interaction strengths in the Nd-doped systems were evaluated.

Photoacoustic Spectra Studies on Neodymium Complexes

A series of neodymium complexes crystals were synthesized and their photoacoustic spectra were determined. The excited state energy levels of Nd(III) in different complexes were discussed and their...

Polarized absorption of Nd3+ in LiNbO3: Effect of MgO codoping

A systematic investigation is presented of the polarized optical absorption of the Nd3+ ion in LiNbO3 and LiNbO3(MgO) crystals. Energy levels of Nd3+ are identified and labeled by appropriate crystal quantum numbers μ=1/2 or μ=3/2, in agreement with C3 local symmetry. The anisotropic Judd–Ofelt theory is applied to estimate spectroscopic parameters relevant for laser applications (radiative lifetimes and branching ratios from the 4F3/2 laser state). Fluorescence lifetimes are also determined to estimate the quantum efficiency from the 4F3/2 state: η=0.6 for LiNbO3:Nd and η=0.5 for LiNbO3(MgO):Nd. The effect of MgO codoping in the energy levels as well as in the spectroscopic parameters of the Nd3+ ion is evaluated and discussed.

Deconvolution by derivative operation

A new method of deconvolution by derivative operation has been proposed. By using B spline to smooth the data, a section of Nd3+ fluorescence spectrum near 880 nm obtained at room temperature was treated. The spectral resolution was improved greatly, and the 4I9/2 and 4F3/2 energy levels of Nd3+ in laser glass were determined by the new method. For recovery of spectra in which the intrinsic line shape is Gaussian, this method has better characteristics, such as fewer selected parameters, simpler calculation, and faster operation speed, and is superior to previous deconvolution approaches.

Energy levels of Nd 3+ and Eu 3+ in zircon- and monazite-type structures

Energy levels of Nd 3+ and Eu 3+ in zircon- and monazite-type structures

Energy levels of Nd3+ in LiYF4

High-resolution absorption spectra of Nd3+ in LiYF4 were recorded between 3900 and 40 200 cm−1 at temperatures from 10 to 300 K. The levels were obtained by diagonalizing a Hamiltonian that describes the free ion parameters, including two and three-body configuration interactions, as well as the crystal field operator. Calculations were performed using the complete basis of 364 ‖αSLJMj〉 kets of the 4f3 configuration of Nd3+. A set of free ion and crystal field parameters were calculated which fitted energy levels with an rms deviation of 22 cm−1 with respect to 134 experimentally determined levels.

Parametric analysis of the energy levels of Nd 3+ in frozen dilute aqueous solutions of neodymium chloride

A parametric analysis of the Stark-split spectra of Nd 3+ in frozen dilute aqueous solutions of neodymium chloride has been carried out.The similarity of the spectra of Nd 3+ in frozen dilute solutions and in crystals, where the ion is nine-fold coordinated and of approximate D 3h symmetry (Nd 3+: LaCl 3, neodymium ethylsulfate and bromate), was used to obtain initial parameter values. Simultaneous diagonalization of the free ion and crystal field hamiltonians resulted in a r.m.s. deviation σ of 11 cm −1 for 50 levels. The resulting crystal field parameters are B 2 0 = 278 ± 19, B 4 0 = −201 ± 39, B b 0 = −946 ± 55 and B 6 6 = 663 ± 43 cm −1. Selection rules for D 3h are approximately obeyed. The small value of σ, the number of levels accounted for and the fact that the final parameters are not very different from those in the crystals indicate a nine-fold coordination of approximate D 3h symmetry for Nd 3+ in frozen aqueous solutions. The spectra of liquid solutions show by their similarity to the spectra of frozen solutions that the same surroundings exist in the liquid.

Thermodynamics of the lanthanide trifluorides. III. The heat capacity of neodymium trifluoride, NdF3, from 5 to 350 °K

The heat capacity of a well-characterized sample of NdF3 was measured by aneroid adiabatic calorimetry from 5 to 350 ° K. The following results were determined at 298.15 ° K: the heat capacity, Cp= (92.42±0.09) J ° K−1 mole−1; the entropy, S°= (120.79±0.12) J °K−1 mole−1; the enthalpy increment, [H ° (298.15 °K)−H° (0)]=17 360±17 J mole−1; and the Planck function, −[G° (298.15° K)−H ° (0)]/T= (62.56±0.06) J ° K−1 mole−1. The values of the last three functions were adjusted for the removal of the degeneracy associated with the ground-state Kramer’s doublet of Nd+3. A table of recommended thermal functions of NdF3 from 400 to the melting temperature, 1650 °K is presented. The excess heat capacity due to the internal electronic energy levels of Nd+3 was calculated from spectroscopic data and also from calorimetric results and the two calculations were found to be in reasonable agreement.

Spectroscopic properties and laser performance of Nd3+ in lanthanum beryllate

The neodymium-doped lanthanum beryllate (La2Be2O5 : Nd3+ or BEL : Nd) laser crystal is monoclinic, space group C2h6-C2/c. The fundamental vibration directions of light and the corresponding refractive indices have been determined as a function of wavelength. At 1 μm the indices are nX=1.9641, nY=1.9974, and nZ=2.0348. The energy levels of Nd3+ for the five lowest manifolds are presented. The low concentration limit for the Nd3+ 4F3/2 fluorescent lifetime in this crystal is 150 μsec and the two observed laser transitions have stimulated emission cross sections of 2.1×10−19 cm2 for E∥X and 1.5×10−19 cm2 for E∥Y. The laser wavelengths are 1.070 and 1.079 μm, respectively. In laser testing a higher slope efficiency was obtained in La2Be2O5 : Nd than in Y3Al5O12 : Nd (YAG : Nd). A Q-switched output of 450 mJ from a 6.4-mm-diam by 76-mm-long X-axis rod of BEL : Nd has been achieved for the 1.079-μm transition, while a YAG : Nd rod of the same size in the same system yielded 160 mJ. The higher Q-switched output in BEL : Nd is consistent with the lower stimulated emission cross sections as compared to that of YAG : Nd.

Absorption and luminescence spectra and energy levels of Nd3+ and Er3+ ions in LiNbO3 crystals

Absorption and luminescence spectra and energy levels of Nd3+ and Er3+ ions in LiNbO3 crystals

Energy levels of Nd(IV) and Er(IV) in Y2O3

The free-ion energy levels of Nd(IV) and Er(IV) in Y2O3 are expanded in a Taylor series, taking the effects of both linear and nonlinear configurational interactions into account. Numerical values of the partial derivatives of the energy levels with respect to F2, F4, F6, ξ, α, β, Y(22,1), and Y(22,3) are tabulated. The r.m.s. deviation in the case of Nd(IV) is improved from 90 cm−1 to 48 cm−1 and, in the case of Er(IV), the r.m.s. deviation is improved from 61.5 cm−1 to 43 cm−1. The improvements are the result of the inclusion of the extra parameters.

Configuration-Interaction Effects on the ``Free-Ion'' Energy Levels of Nd3+ and Er3+

By the use of three or four parameters of configuration interaction, the experimental ``free-ion'' energy levels of Nd3+ and Er3+ have been fitted with an rms deviation of 45–55 cm−1. The significance of the various parameter values is discussed. It is also shown that assignments based purely on comparison with a calculation using only F2, F4, F6, and ζ may occasionally be in error. Several discrepancies in previous work are now cleared up.