Experimental determination of penetration parameter forM1 conversion,and theE2 admixtures for 77 and 191 keV transitions in197Au

TheL-subshell conversion for 77 keV transition andK,L ₁,L ₂-shell conversion for 191 keV transition in¹⁹⁷Au, as well asK-shell conversion transition of 158 keV in¹⁹⁹Hg were measured by means of Π√2-iron free electron spectrometer. Relative gamma-ray intensities have been determined by Ge(Li) spectrometer. From these measurements the α _K conversion coefficient value has been deduced for 191 keV transition as α_K(191 keV)=0.86±0.03. This value shows that the spin of the level at 268 keV in¹⁹⁷Au is 3/2⁺. For the penetration parameter (λ) and intensity ratio \(\left( {\delta ^2 = \frac{{\left\langle {E2} \right\rangle ^2 }}{{\left\langle {MI} \right\rangle ^2 }}} \right)\) the following values are obtained: $$\begin{gathered} \lambda = 3.4 \pm _{1.5}^{1.9} \delta ^2 = 0.11 \pm 0.03for 77 keV transition \hfill \\ \lambda = 3.2 \pm _{0.6}^{0.8} \delta ^2 = 0.17 \pm 0.04for 191 keV transition. \hfill \\ \end{gathered} $$ The agreement of these results with the predictions of De Shalit model is discussed.     

Some insight into the structure of the nuclei 19F, 19Ne, 21Ne, 21Na, 23Na and 23Mg through the generator coordinate method and the projected Hartree-Fock method

Structures of two sets of mirror nuclei ¹⁹Ne, ²¹Na, ²³Mg and ¹⁹F, ²¹Ne, ²³Na were studied comparatively by means of the electromagnetic properties of the even-parity states, calculated with the generator coordinate method and with mixing of projected Hartree-Fock determinants. The present results are compared with those of complete diagonalization. In particular, collective features of these nuclei are investigated by comparing the various microscopic results with the predictions of the simple rotational model.     

The X-ray diffraction and electron microscopic investigation of stable and metastable equilibria in Al-rich Al-Zn alloys

The solvus line for the metastable cubic α′-phase and for the stable α- and α′-solubility limit for Al-Zn alloys with zinc content from 15 to 50 wt.% were determined. X-ray diffraction on single crystals was used to study the structures of phases developed during the applied heat-treatments. The dissolution of α′-phase at temperatures close below and above the determined solvus temperatures was observed by the transmission electron microscopy. The shift of the known (α+α′)-phase boundary to lower temperatures of about 8 °C was found. Similarly, small changes were obtained in the shape of the curve giving the solid solubility limit of Zn in Al.     

Residual entropy of the one-dimensional Ising antiferromagnet with general spin

We have calculated the ground-state degeneracy and the concominant residual entropy of the one-dimensional Ising antiferromagnet in a critical magnetic field. We demonstrate that the results obtained can be related to the ground-state properties of the q-state Potts antiferromagnet in the corresponding external field.     

Non-uniqueness of the heat current operator and the hopping thermoelectric and Nernst-Ettingshausen effects in amorphous semiconductors

The Hardy correction in the heat current operator is generalized to the case of non-zero electron-phonon coupling constantg. It is then shown that not only the lowest (minus first) order but also the fist order contribution ing to the thermoelectric power of amorphous semiconductors in the hopping regime disappears. Consequently, since the lowest (zero) order contribution to the thermoelectric effects in the magnetic field yields no Nernst-Ettingshausen effect in these materials, the last effect is of the second order ing, at least.