A study of the magnetic,molecular and electronic structure of some alkali biphenyl ion pairs in the solid state

A magnetic resonance and susceptibility study of the molecular and magnetic structure of some alkali biphenyl (Bp) polyglyme single crystals and powders has been performed. For RbBp · 2Ttg (Ttg=tetraglyme), space group C2/c, and NaBp · 2Tg (Tg=triglyme), space group P2₁, the average g tensors have been measured. From the average g tensor and the known crystal structure of RbBp · 2Ttg the molecular g tensor of the Bp anion could be derived. The molecular g tensor was calculated with Stone's theory. Excellent agreement was found with the experimental values. With the aid of the molecular g tensor of the Bp anion and the average g tensor of NaBp · 2Tg, for which the crystal structure is unknown, the orientation of the symmetry axes of Bp with respect to the crystal axes could be calculated. Susceptibility measurements reveal ferromagnetic coupling in both KBp · 2Ttg and NaBp · 2Tg, whereas antiferromagnetic coupling exists in RbBp · 2Ttg. The results of alkali N.M.R. experiments are related to the molecular structure. A lower limit is found for the electrical conductivity of NaBp · 2Tg.     

Untersuchung von Honig

Ohne Zusammenfassung     

Untersuchung von Honig und Honigkuchen

Ohne Zusammenfassung     

Two-Phase Flow and the Capillarity Phenomenon in Porous Solids – A Continuum Thermomechanical Approach

Two-phase flow and capillarity phenomenon in porous solids, well known in physics and engineering, are treated from a rigorous continuum thermomechanical point of view for the first time. A ternary model, consisting of a porous solid phase, a liquid phase, and a gas phase, is investigated within the framework of thermodynamics. The main result of the evaluation of the entropy principle turns out to be that the interaction forces between the solid, gas, and liquid phases are dependent on the free Helmholtz energy functions of the corresponding phases and on the gradient of the liquid density. The classical result for the driving volume force for raising a water column in a narrow tube against the force of gravity is contained in the general investigation.     

Gamma-ray spectroscopy of87Y

The level structure of⁸⁷Y has been studied using in-beam γ-ray spectroscopic methods. Many previously unknown states have been observed. Members of theπ(g _9/2 )ν(g _9/2)^?2 multiplet are identified. The results are discussed in terms of the weak-coupling model.     

The decay properties of 3.25 min 169Hf and 2.05 min 167Hf

The decays of 3.25 min ¹⁶⁹Hf and 2.05 min ¹⁶⁷Hf have been studied with high-resolution Ge(Li) and Si(Li) detectors. The total decay energy of ¹⁶⁹Hf determined from our experimental $\text{K}\text{β}{}^{\mathrm{+}}$ ratio is 3.29^+0.05_?0.13 MeV. The allowed unhindered character of the main β-branches in the decay of both isotopes allows unique Nilsson model assignments.     

Effect of ordering transformation rate on the magnetic properties of Fe–Pt-based bulk alloys

We have investigated the ordering transformation and magnetic properties of Fe_59.75Pt_39.5Nb_0.75 bulk alloys in detail by using different high-temperature homogenization treatments, different cooling rates and different low-temperature annealing treatments to obtain samples with different microstructure and different atomically ordered states. The quenching rate after the high-temperature homogenization treatment was chosen much lower than in previous investigations. In this way, we were able to obtain nanostructured bulk alloys consisting exclusively of the hard-magnetic face-centered-tetragonal phase. A high remanence ratio was obtained by profiting from the nanocomposite exchange coupling between nearest-neighbor-ordered regions. The present results are compared with results of previous investigations in which much higher cooling rates were applied. We also discussed why the present alloy systems are less suitable for the attainment of exchange spring behavior.