Verbindungsbildung in den quasi-binären Systemen AcX4?MX2 (Ac = Th,U; M = Ca,Sr, Ba,Eu, Ge,Sn, Pb; X = Br,I)

Formation of Compounds in the Quasi-binary Systems AcX₄? MX₂ (Ac = Th, U; M = Ca, Sr, Ba, Eu, Ge, Sn, Pb; X = Br, I) T,x-phase diagrams of the systems ThI₄? SnI₂, ThI₄? PbI₂, ThI₄? CaI₂, and ThI₄? SrI₂ were established using thermoanalysis and x-ray methods. The only ternary compounds have a 1:1 composition. Further AcMX₆ compounds (Ac: Th, U; M: Ca, Sr, Ba, Eu, Ge, Sn, Pb; X: Br, I) were synthesized and their structures investigated. Four structure types are found depending on the temperature and the Ac/M combinations. The structures of γ-ThSnI₆ and β-ThSnI₆ were determined with single crystal methods as representatives of a whole series of isotypic compounds.     

Phonon spectral function of a superconductor

The phonon spectral function of an acoustic phonon in a BCS superconductor is calculated at zero temperature and compared to the result for the normal metal. Shifts are found in the frequency and linewidth of the phonon depending on its wavevector. In addition to the phonon, the spectral function shows a structure around the gap energy of the superconductor, reflecting the increased polarizability of the superconducting electrons at this energy.     

Critical behavior and coexistence near a superconducting-ferromagnetic multicritical point

It is shown that in the vicinity of the multicritical transition point of a ferromagnetic cuperconductor a) critical fluctuations of the superconducting order parameter should become observable in 3 dimensions, b) for planar magnetic ordering magnetism and superconductivity should coexist.     

Eine gravimetrische Bestimmung von Metallen und Wasser in organischen Verbindungen

Ohne Zusammenfassung