Search results for "HYPERFINE STRUCTURE"

Ferromagnetic ordering in GdPdCd

2010

Abstract GdPdCd was obtained in pure form via reaction of the elements in a sealed tantalum tube in a high-frequency furnace. The structure was investigated by X-ray diffraction on both powders and single crystals: ZrNiAl type, P 6 2m , a=758.2(1), c=391.78(7) pm, wR2=0.0410 for 358 F2 values and 14 variables. Striking structural motifs of GdPdCd are two types of palladium-centered tricapped trigonal prisms [Pd1Cd3Gd6] and [Pd2Cd6Gd3]. Together the palladium and cadmium atoms build a three-dimensional network in which the gadolinium atoms fill distorted pentagonal channels. Susceptibility measurements reveal Curie–Weiss behaviour with an effective magnetic moment of 8.2(1) μB/Gd. GdPdCd ord…

The bromine nuclear quadrupole moment revisited

2013

For the bromine atom and the hydrogen bromide molecule, we report results for the electric-field gradient at the bromine nucleus based on quantum-chemical calculations. Highly accurate values are obtained by using coupled-cluster methods for the treatment of electron correlation, by minimising remaining basis-set effects through the use of large atomic-orbital sets, and by taking into account relativistic effects. For hydrogen bromide, zero-point vibrational corrections are considered as well. The obtained results for the bromine electric-field gradients are used to derive values for the Br-79 quadrupole moment: 308.1 and 309.3 mb based on data for the bromine atom and hydrogen bromide, res…

Chemical Applications of Mössbauer Spectroscopy

2012

The Tutorial Lecture begins with a brief recapitulation of the hyperfine interactions and the relevant parameters observable in a Mossbauer spectrum. The main chapter with selected examples of chemical applications of Mossbauer spectroscopy follows and is subdivided into sections on: basic information on structure and bonding; switchable molecules (thermal spin transition in mono- and oligonuclear coordination compounds, light-induced spin transition, nuclear-decay-induced spin transition, spin transition in metallomesogens); mixed-valency in biferrocenes and other iron coordination compounds, and in an europium intermetallic compound; electron transfer in Prussian blue-analog complexes; mo…

Experimental study of the long range interactions between a Na (3S) and a Rb (5S) atom

2005

Transitions to near asymptotic levels of the a3Σ+ and the X1Σ+ electronic states in NaRb were recorded by high resolution Fourier transform spectroscopy technique. The hyperfine splitting of the a3Σ+ state levels was analysed. The application of coupled channels calculations is discussed for determination of accurate potential energy curves of the a3Σ+ and the X1Σ+ states capable for reliable description of cold collisions between a Na and a Rb atoms in their ground states.

Orientation of the electric field gradient and ellipticity of the magnetic cycloid in multiferroic BiFeO3

2016

This work was supported by Uniwersytet Pedagogiczny.

Metall-π-Komplexe von Benzolderivaten, XII Hyperfeinstruktur und Linienbreiten in den ESR-Spektren methylierter und deuterierter Bis(η-benzol)chrom(I…

1979

Die vollstandige Reihe der Methyl-Substitutionsprodukte des Bis(η-benzol)chrom(I)+·-Radikalkations sowie ausgewahlte deuterierte Derivate desselben wurden in Losung und in glasartig erstarrtem Medium ESR-spektroskopisch untersucht. 1H-, 2D- und 53Cr-Hyperfeinparameter werden mitgeteilt und das Proton/Deuteron-Kopplungskonstantenverhaltnis wird diskutiert. Die Betrage von a(1HAren) und a(1HMethyl) variieren innerhalb enger Grenzen (3,454,15 bzw. 0,50,7 G), wobei a(1HAren) mit zunehmendem Methylierungsgrad zunimmt. Um die Konformationsabhangigkeit von a(1HMethyl) zu studieren, werden die ESR-Spektren von (η12-[2.2]Paracyclophan)-chrom(I)+·, 21+·, und Bis(1,4-dimethyl-η6-benzol)chrom(I)+·, 5+·…

Rotational spectrum of silyl chloride: hyperfine structure and equilibrium geometry

2012

The Lamb-dip technique was employed to record the rotational spectra of two isotopic species of silyl chloride, namely (28)SiH3Cl and (29)SiH3Cl, in order to investigate their hyperfine structure. High-accuracy quantum-chemical computations were employed to predict the hyperfine parameters involved and to support the experimental investigation. Analysis of the experimental spectra led to an improvement in the accuracy of the known spectroscopic constants as well as allowed us to determine additional spectroscopic parameters for the first time. Furthermore, the equilibrium structure of silyl chloride was reinvestigated using both theoretical and experimental data. The best theoretical and se…

Direct detection of 17O NMR in [Gd(DOTA)]- by NMR Spectroscopy

2015

The 17O NMR spectrum of the non-coordinated carboxyl oxygen in the GdIII-DOTA (DOTA = tetraazacyclododecanetetraacetic acid) complex has been observed experimentally. Its line width is essentially unaffected by paramagnetic relaxation due to gadolinium, and is only affected by the quadrupole pathway. The results are supported by the relevant parameters (hyperfine and quadrupole coupling constants) calculated by relativistic DFT methods. This finding opens up new avenues for investigating the structure and reactivity of paramagnetic GdIII complexes used as contrast agents in magnetic resonance imaging.

Laser developments and high resolution resonance ionization spectroscopy of actinide elements

2014

Shape staggering of midshell mercury isotopes from in-source laser spectroscopy compared with density-functional-theory and Monte Carlo shell-model c…

2019

Neutron-deficient Hg177-185 isotopes were studied using in-source laser resonance-ionization spectroscopy at the CERN-ISOLDE radioactive ion-beam facility in an experiment combining different detection methods tailored to the studied isotopes. These include either α-decay tagging or multireflection time-of-flight gating for isotope identification. The endpoint of the odd-even nuclear shape staggering in mercury was observed directly by measuring for the first time the isotope shifts and hyperfine structures of Hg177-180. Changes in the mean-square charge radii for all mentioned isotopes, magnetic dipole, and electric quadrupole moments of the odd-A isotopes and arguments in favor of I=7/2 s…