Paramagnetische Relaxation von CeCl3·7H2O im Temperaturbereich von 1,1 bis 4,2°K

The paramagnetic relaxation of a single crystal of CeCl₃·7H₂O has been studied by the dispersion-absorption-method at temperatures between 1,1 and 4,2°K. Alternating magnetic fields with frequencies between 5 and 2660 Hz and parallel magnetic fields up to 4000 Oe have been used. The spin lattice relaxation time has been determined as a function of temperature. At two special rangesH ₁ andH ₄ of the magnetic field a second, temperature-independent dispersion-absorption region has been observed besides the temperature-dependent spin-lattice relaxation (double relaxation). At two other special magnetic fieldsH ₂ andH ₃ the anomalous field dependence of the high frequency adiabatic susceptibility suggests a second dispersion-absorption-region ocurring at frequencies, which we cannot attain experimentally. In all cases cross relaxation processes are combined with the spin lattice relaxation.     

Die optischen Konstanten des Kaliums im Wellenlängenbereich von 3650 bis 20000 Å

The optical constantsn andk of the alkali metal potassium have been measured in the wavelength region from 0·365μ to 2μ, in the solid and liquid state at temperatures between ?180° C and +85° C by the usual method of analysing intensity and polarisation of the monochromatic radiations reflected by the metals surface. The mirrorlike surfaces, free of any contamination and not distorted by any treatment, were prepared and measured in ultrahigh vacuum, the metal being purified before by careful repeated destinations in high vacuum. Values thus obtained forn, k, k ²?n ² and 2nk are listed in tables 1 and 2. Discussion of these values especially with regard to the Drude-theory of optical constants of metals is given in two subsequent communications.     

Die Winkelverteilung im Bereich 30 bis 155° von elastisch an Golddampf gestreuten Elektronen mit Energien zwischen 150 und 1900 eV

The angular distribution of electrons scattered elastically by gold atoms has been investigated over the angular range from 30 to 155° and with electron energies between 150 and 1900 eV. The scattering curves obtained resemble closely the corresponding curves for mercury atoms. The theoretically expected energy dependence of the 90°-scattering is in poor agreement only with the results obtained experimentally in this work.     

Die Pendelvervielfachung von Sekundärelektronen im Dezimeterwellengebiet

The conditions as deduced from theory for the existence of secondary electron resonance mechanism (dynamic multiplication of secondary electrons) are tested in the decimeter wave range. A re-entrant cavity resonator is used for this the field length of which can be varied at its field maximum. For the voltage amplitude at the start of multiplication the quadratic dependence on the length of field — as postulated by theory — is completely confirmed. For the voltage amplitude at the instant of break-off the experiments, however, yield for small lengths of field higher values than calculated.