Time Differential Perturbed Angular γγ-Correlation Studies of Diethylenetriaminepentaacetic Acid Complexes with 111\text{}^{111}In and 111m\text{}^{111m}Cd

Static and dynamic electric quadrupole interactions of $\text{}^{111}$Cd in complexes with diethylenetriaminepentaacetic acid were studied by the time differential perturbed angular γγ-correlation technique using two parent isotopes, $\text{}^{111}$In(EC)$\text{}^{111}$Cd and $\text{}^{111 m}$Cd. The measurements were carried out using neutral aqueous solutions of the diethylenetriaminepentaacetic- acid-complexes with initial isotopes at 293 K and 77 K. It was shown that the $\text{}^{111}$Cd-diethylenetriaminepentaacetic-acid-complex in aqueous solutions at pH = 7.0 is characterised by the re-orientational correlation time of 7.7×10$\text{}^{-11}$ s and an electric field gradient V$\text{}_{zz}$=6.7(2)×10$\text{}^{21}$ V/m$\text{}^{2}$ with an asymmetry parameter η=0.75(5). A direct comparison of the electric quadrupole interaction parameters for diethylenetriaminepentaacetic- acid-complexes with $\text{}^{111}$In and $\text{}^{111m}$Cd confirmed the proposal about the fragmentation of the complexes caused by the after-effects of electron capture in $\text{}^{111}$In. An observed difference in the electric quadrupole interaction parameters obtained for the solutions with $\text{}^{111}$In and $\text{}^{111m}$Cd complexes reflects a process of a chemical rearrangement of the complex structure after the In decay into C

Pd-vacancy complex in Si identified with the perturbed angular correlation technique

A Pd-vacancy (Pd-V-) complex in Si has been identified with the perturbed angular correlation technique using the radioactive Pd-100 probe produced by recoil implantation. The fraction of Pd probes in the complex has been determined as a function of dopant type (B, P, As, and Sb), dopant concentration (10(15)-6x10(19) cm(-3)) and annealing temperature (21-500 degrees C). The Pd-V- complex, with a unique interaction frequency of 13.1(2) MHz, was observed only in n(+)-Si with a maximum relative fraction of similar to 52% achieved between 200-300 degrees C while a broad distribution of interaction frequencies was apparent in n-, p-, and p(+)-Si. Annealing beyond 300 degrees C yielded a reduction in the Pd-V- fraction with a dissociation energy of 2.5(7) eV. Density functional theory calculations of the electric field gradient for the given defect configuration were consistent with a measured value of 3.58x10(21) V/m(2)