Temperature dependence of hyperfine fields in intermediate valent140CeLa and140CeLu

The hyperfine fields for the systems¹⁴⁰CeLa and¹⁴⁰CeLu have been determined by time differential perturbed angular correlations (TDPAC) in the temperature range 4.2 K≤T≤330 K. Magnitude and temperature dependence of the paramagnetic enhancement factor β indicate that cerium in either system is of intermediate valence. This behaviour is discussed in terms of a theory proposed by Ramakrishnan et al. [1–3].     

Nuclear orientation of106Rh in iron

The anisotropy of -rays from the decay of oriented¹⁰⁶Rh nuclei was studied at temperatures between 14 and 100 mK. The ground state magnetic moment was determined to be |(1⁺)|=3.07(9) n.m. Incomplete orientation was observed which is assumed to result from relaxation during the 43 s lifetime of the decaying nucleus.     

Development of a digital freeprogrammable function generator for high precision double motion Mössbauer-drives

Construction and use of a function generator are presented. The flexible outline allows a high precision control for all required velocity profiles.     

Hyperfine spectroscopy in diffraction geometry

Hyperfine Interactions - With the advent of third generation synchrotron radiation sources nuclear Bragg diffraction became a powerful technique for the determination of hyperfine parameters and...     

Determination of the mean life of some excited nuclear states by Moessbauer experiments

Mean lives of several excited nuclear states have been determined using the Moessbauer effect. The mean life is deduced by interpolating the experimental line width to zero effective thickness of the resonance absorber. An improved expression is used for the interpolation. The results are: τ(140 keV level of⁹⁹Tc)=277(14)ps τ(136 keV level of¹⁸¹Ta)=55 (3)ps τ(129 keV level of¹⁹¹Ir)=129 (2)ps τ(139 keV level of¹⁹³Ir)=115 (3)ps τ(77 keV level of¹⁹⁷Au)=2.73 (2)ns.     

Time-dependent electric quadrupole interactions in (NH4)3HfF7

Spinrotation spectra of polycrystalline (NH₄)₃HfF₇ in which radioactive¹⁸¹Hf was incorporated have been measured in the temperature range from ?196 °C to + 70 °C. The spectra were interpretated on the base of the stochastic model of M. Blume. It was assumed that reorientations of the [HfF₇]^3? polyhedra take place at random. The resulting fluctuation rates can be understood as to be caused by an activation process. The activation energy was determined to 0.324(12) eV in agreement with NMR measurements on¹⁹F in this compound.     

Derg-Faktor des 364 keV-Zustandes von184W und die Hyperfeinfelder von Wolfram in Eisen,Kobalt und Nickel

Theg-factor of the 364 keV state of¹⁸⁴W was measured by the time integral angular correlation method using the high hyperfine fields at the tungsten nucleus in iron. The same experiment was performed with the 111 keV state giving the ratiog(364 keV)/g(111 keV)=1.02(14). Using this ratiog(364 keV-level)=0.286(35) was deduced. For the hyperfine fields of W in Fe, W in Co and W in Ni at 300 K ?610(35) kG, ? 358(23) kG and ?80(3) kG respective have been determined.     

Die magnetischen Momente der 5−-Niveaus von Sn118 und Sn120

The rotations ofγγ-angular correlations in strong external magnetic fields were observed in the decay of 5.1h Sb¹¹⁸ and 5.8d Sb¹²⁰. Values of the gyromagnetic ratios of the 5^? two particle states of Sn¹¹⁸ and Sn¹²⁰ were derived. In the case of 5.1 hours Sb¹¹⁸ the rotation of the 254 keV-1.221 MeVγγ-angular correlation in a field of 40950 Gauss was measured as

$$\omega _L \cdot \tau = 0 \cdot 417 \pm 0 \cdot 038,$$