[en] The cranked modified oscillator potential is used to study the nuclei ^172-180₇₂Hf at very high angular momenta. All these isotopes are found to 'rotate around the prolate symmetry axis' for spin values I=15-40h/2π. In this region of spin one then looks for prolate yrast traps. The pairing interaction with an approximative particle number projection as well as the hexadecapole degree of freedom are taken into account. The calculated traps agree fairly well with experiments. Additional traps are predicted, the highest at spin 39h/2π. (Auth.)

[en] Isotope shifts in the optical transitions of Hf I with wavelength 590.3 and 594.8 nm have been measured using high resolution laser spectroscopy. The charge radii differences of Hf nuclei in the range A=174-182 were determined. The comparison of obtained data with droplet model calculations was performed. The change of deformation for Hf nuclei at neutron number increase is discussed

[en] The cross sections for the production of isomeric states in the reactions ¹⁷⁹Hf(n,2n)^178m2Hf, ¹⁸⁰Hf(n,2n)^179m2Hf, ¹⁷⁹Hf(n,n')^179m2Hf with 14 MeV neutrons have been measured and compared with the theoretical ones. 4 refs, 3 figs, 4 tabs

[en] High-resolution laser spectroscopy has been used to measure the isotope shifts for optical transitions in HfI with wavelengths of 590.3 and 594.8 nm. The charge radii of Hf nuclei over the mass-number range A=174-182 have been determined. The results found are compared with calculations from the liquid-drop model. The change in the deformation of the Hf nuclei with increasing neutron number is discussed. 29 refs., 6 figs., 4 tabs

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[en] Bomb reduction of HfF₄ with Na results in Hf metal sufficiently pure to prepare self-supporting Hf targets of 100-350 μg cm^-2 thickness by high vacuum sputter deposition. A necessary condition for the success of the procedure is the capability to convert HfO₂, the standard chemical inventory form of enriched Hf isotopes, into HfF₄, which is free from oxyfluoride admixtures. This is also described in some detail. Targets of the isotopes ¹⁷⁶Hf, ¹⁷⁷Hf, ¹⁷⁸Hf, ¹⁷⁹Hf and ¹⁸⁰Hf have been prepared by this method. (orig.)

[en] G-factors of rotational states in ¹⁷⁶Hf and ¹⁸⁰Hf were measured with the twelve detector IPAC-apparatus of our laboratory. The natural radioactivity 3.78 .10¹⁰y¹⁷⁶Lu and the 5.5 h isomer ^180mHf were used which populate the ground-state rotational bands of ¹⁷⁶Hf and ¹⁸⁰Hf. The integral rotations of γ-γ directional correlations in strong external magnetic fields and in static hyperfine fields of (Lu→Hf)Fe₂ and HfFe₂ were observed. The following results were obtained: ¹⁷⁶Hf: g(4⁺₁)=+0.334(38) ¹⁸⁰Hf:g(2⁺₁)=+0.305(14) g(4⁺₁)=+0.358(43) g(6⁺₁)/g(4⁺₁)=+0.95(12). The hyperfine field in (Lu→Hf)Fe₂ was calibrated by observing the integral rotation of the 9/2^- first excited state of ¹⁷⁷Hf populated in the decay of 6.7d ¹⁷⁷Lu. The g-factor of this state was redetermined in an external magnetic field as ¹⁷⁷Hf: g(9/2^-)=+0.228(7). Finally the g-factor of the 2⁺₁ state of ¹⁷⁶Hf was derived from the measured g(2⁺₁) of ¹⁸⁰Hf by use of the precisely known ratio g(2⁺₁,¹⁷⁶Hf)/g(2⁺₁,¹⁸⁰Hf) as ¹⁷⁶Hf: g(2⁺₁)=+0.315(30). (orig.). With 17 figs., 4 tabs

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