TDPACs

Radioactive Ru is dilutely doped in Fe304. The value of the magnetic hyperfine field (at the Ru nucleus) obtained by TDPAC at 10 K (—16 T) is essentially in agreement with that derived from the Mossbauer spectrum at 5 K (14.5 T). The negative sign of means that the Ru ions... 

SRPAC is a scattering variant of time-differential perturbed angular correlation (TDPAC). In TDPAC, an intermediate nuclear level is populated from above after the decay of a radioactive parent. If this nuclear level exhibits hyperfine... 

A. V. Salamatin, N. A. Korolev A. 1. Velichkov, et al., Electric field gradients in MgB2 synthesized at high pressure Cd TDPAC study and ab initio calculation. Solid State Commun., 2001,119,153-158. 

The first observation of Zn NMR in zinc metal was by Abart and coworkers in a measurement at 4.2 K, using a field sweeping technique, which yielded a value of = 12 73(4) MHz. No subsequent NMR observation has been reported. A measure of the temperature dependence of the Zn nuclear quadrupole coupling in zinc metal has been obtained from time differential perturbed angular correlation (TDPAC) measurements using an excited state of Zn (/ = 9/2 605 keV). However, the use of liquid helium temperatures and exotic short-lived isotopes precludes the adoption of these techniques for general material characterization. 

See lext. XD = X-ray diffraction 1R = infrared spectrum R = Raman spectrum UV = ultraviolet spectrum H-NMR = ]HNMR spectrum C-NMR = 13CNMR spectrum F-NMR =, 9FNMR spectrum MS = mass spectrum PES — photoelectron spectrum E - electric polarization and dielectric loss measurements D = dipole moment measurements TDPAC = time differential perturbed angular correlation measurements GC = gas chromatography TA = thermal analysis M = molecular weight A = electrical conductance. c Isolated as the THF adduct M(dik)Cl3-C4HgO. 

An inexpensive target system for the production of the NCA radioisotope, 77Br323,324, has been described recently325 and applied for time differential perturbed angular correlation (TDPAC) studies which provide information of physical interest. TDPAC has also found application in the field of chemistry326 and biology31. 

Time Differential Perturbed Angular Correlation (TDPAC)... 

Hyperfine interactions, that is the interaction of a nuclear magnetic moment with extranuclear magnetic fields and the interaction of a nuclear quadrupole moment with electric field gradients from extranuclear charge distributions, are measured via time differential perturbed angular correlation (TDPAC) of y-rays emitted from radioisotopes. 

Reviews on PAC theory, applications of TDPAC in materials science and chemistry, in the border region between physics, chemistry, and biology, and in biology as well as a comprehensive compilation of NQl-data obtained by TDPAC can be found under References. 

Further investigations dealt with structural phase transitions. In general, structural phase transitions are easily detected in diffraction studies or by differential thermal calorimetry. However, freqnently snch transitions are accompanied by local dynamics of atoms on snblattices prior to the transition which are not readily observed by diffraction techniqnes. Here, the lattice dynamics which shows np in the TDPAC spectra are of particnlar valne in understanding the origin of the phase transition. 

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... 

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

Biochemical studies indicate that radiohafnium ( Hf+ Hf) is bound mainly to the transferrin, in blood plasma and in the liver cytosol of both the rat and the hamster, as has been observed also for plutonium (Taylor etal. 1983). Two specific electric quadrupole interactions have been observed in the binding of hafnium to transferrin in sera of humans and rats, using the time differential perturbed angular correlation (TDPAC-) technique (Then et al. 1986, Appel et al. 1987). They may be attributed to the N-terminal and the C-terminal binding sites in the transferrin molecule. 

Appel H, Duffield J, Taylor DM, Then GM and Thies WG (1987) TDPAC studies of the metalbinding sites in serum tranferrin comparison between ISlHf-labeled human- and rat-serum transferrin. J Inorg Biochem 31 229—239. 

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