Perturbed angular correlation spectroscopy

TDPAC time differential perturbed angular correlation (spectroscopy)... 

Time differential perturbed angular correlation spectroscopy, 353 Time, dimensionless, 535 Time resolved laser induced fluorescence spectroscopy, 349, 350 Titanates... 

R. Bauer, Perturbed angular-correlation spectroscopy and its application to metal sites in proteins—possibilities and limitations, Q. Rev. Biophys. 1985, f8(l), 1-64. 

PAD (perturbed angular distribution) is a variation of PAC with nuclear excitation by a particle beam from an accelerator. QMS is quasielastic MdBbauer-spectroscopy, QNS is quasielastic neutron spectroscopy. For MOBbauer spectroscopy (MS), perturbed angular correlation (PAC), and /J-nuclear magnetic resonance (/3-NMR), the accessible SE jump frequencies are determined by the life time (rN) of the nuclear states involved in the spectroscopic process. Since NMR is a resonance method, the resonance frequency of the experiment sets the time window. With neutron scattering, the time window is determined by the possible energy resolution of the spectrometer as explained later. 

Besides NQR spectroscopy and the study of nuclear quadrupole interaction effects in broad-line NMR spectroscopy, paramagnetic electron resonance 6°1, Mossbauer spectroscopy, and the study of perturbed angular correlation of y-rays, are suitable methods for studying nuclear quadrupole interactions in solids. Indirect methods are also available for acquiring information about the nuclear quadrupole couplinjg constant from the liquid state (particularly NMR spectroscopy in liquids and in liquid crystals in some cases gives information about this constant). By microwave spectroscopy, the nuclear quadrupole interaction may be studied in the gaseous phase (see the paper by Zeil). We shall deal here only with the aspect of NQR spectroscopy in solids since this method has the broadest applicability to chemical problems in comparison with the other methods mentioned. 

Time differential perturbed angular correlation (TDPAC) spectroscopy provides information about chemical environment of nuclei whose decay results in a 7-7 cascade. This method allows to study sorbed ions at very low concentrations, but the number of suitable nuclei, i.e. isomeric nuclei having life times sufficient to prepare the sample ( " Cd, Pb) is limited. Decay of / -active nuclides often... 

One less-well-known technique, which has many experimental aspects in common with Mossbauer spectroscopy, deserves special attention at this point, since it gives valuable information about the electric-field gradients and the magnetic hyperfine interactions of radioactive nuclei in solids at ambient conditions and under pressure. In this technique, two y-rays with different energies from two different transitions of an individual nucleus in a radioactive-decay cascade are recorded consecutively. The spatial and temporal perturbation of the emission probability by the hyperfine fields is registered in the corresponding perturbed angular correlation (PAC) spectra. 

Iranzo O, Thulstrup PW, Ryu SB et al (2007) The application of Hg NMR and Hg perturbed angular correlation (PAC) spectroscopy to define the biological chemistry of Hg(II) a case study with designed two- and three-stranded coiled coils. Chemistry 13 9178-9190... 

The relaxation effects as probed via the Mossbauer hyperfine interaction can be investigated by other methods which can be regarded as complementary to Mossbauer spectroscopy. The techniques of perturbed angular correlation of gamma rays (PAC) and positive muon spin rotation (pSR) spectroscopy will be briefly discussed here. A more detailed review can be found in Dattagupta (1981). 

J. Mueller and K. Johnston, Ag(I), Pb(II) and Hg(II) Binding to Biomolecules Studied by Perturbed Angular Correlation of y-Rays (PAC) Spectroscopy Function and Toxicity of Metal Ions in Biological Systems , CERN Document Server Preprints, Avail. URL http //cdsweb.cem.ch/record/1156119/files/ INTC-P-259.pdf... 

Tantalum ( Ta) (7=7/2). The perturbed angular correlation (PAC) spectroscopy was used to measure the electric quadrupole interactions (QIs) of the nuclear probes Ta and Cd in Hf02 and Zr02 as a function of temperature and a hydrate surface layer with a H content of 5-10% was detected by MAS NMR. A defect component involving 30-40% of the probe nuclei appears in the Ta PAC spectra by cooling from T> 1200 K. It was found that the temperature dependence of the Ta defect fraction is consistent with a Ta impurity level at Ed 0.9 and 0.6 eV below the hafnia and zirconia conduction band, respectively. 

Hyperfine interaction techniques with implanted radioactive probe atoms turned out to offer a wealth of information to smdy the atomic configuration and possible defect association of implanted probe atoms. Several hyperfine interaction techniques, e.g. Mossbauer Spectroscopy, Perturbed Angular Correlations, Low Temperature Nuclear Orientation, Muon Spin Rotation, and Beta-NMR are making use of implanted radioactive probe atoms. We refer to the proceedings of the Hyperfine Interaction Conferences, held every two or three years, for reports on many of these studies. Except for the earliest conferences, all these proceedings were published in the journal Hyperfine Interactions. 

Marchi, A.J., Lede, E.J., Requejo, F.G., Renteria, M., Irusta, S., Lombardo, E.A., and Miro, E.E. Laser Raman spectroscopy (LRS) and time differential perturbed angular correlation (TDPAC) study of surface species on Mo/Si02 and Mo,Na/Si02. Their role in the partial oxidation of methane. Catal. Lett. 1997, 48, 47-54. 

The application of Mossbauer spectroscopy in diverse fields of qualitative and quantitative analysis is based on the ease with which hyperfine interactions can be observed. The information obtained from Mossbauer spectroscopy may be correlated with other methods by which HI can be examined such as NMR, EPR, ENDOR, PAC (perturbed angular correlations), nuclear orientation and neutron scattering. However, Mossbauer spectroscopy often proves to be experimentally simpler, more illustrative and an efficient method for studying applied problems. Mossbauer nuclei are ideal spies supplying information on both the microscopic and macroscopic properties of solids. 

Other physical techniques that have been used for the study of recoil particles include mass spectrometry, perturbed angular correlations, and Mossbauer spectroscopy. This section is mainly concerned with those aspects of the latter which are relevant to recoil phenomena. 

Keywords circular dichroism electronic absorption electrospray ionization mass spectrometry magnetic circular dichroism metal-thiolate cluster structures metallothionein perturbed angular correlation of y-rays spectroscopy X-ray... 

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