Untersuchung der Neutronendepolarisation von Dy in der Umgebung von magnetischen Umwandlungspunkten

It is possible to determine the dimensions of the ferromagnetic correlation range by depolarisation measurements of polarized thermal neutrons near magnetic transition points, where small magnetic domains (< 10^?4 cm) are present. The dimensions of the magnetic domains of Dy were determined in the temperature range from 4,2 °K to room temperature and in an external magnetic field from 0 to 2,4 kOe. The size of the domains increases with decreasing temperature and increasing external field. For low temperatures a sort of internal coercive force for the wall mobility was observed, which strongly hinders the formation of greater ferromagnetic domains. At the Curie-point the ferromagnetic correlation range shows a continuous transition and goes only slowly to zero when the temperature increases.     

Entstehung von Alkalimetallen bei der Elektronenbestrahlung von Alkalihalogeniden

We have observed additional peaks in the energy loss spectra of NaBr, NaI, KF, KI, and RbF foils, which are caused by the electron impact. They are identified as volume and surface plasma losses of alkali metal particles. The energy loss values are in accord with energy loss data of alkali metal foils. Electron diffraction patterns of the irradiated alkali halide foils showed additional rings of alkali metal agglomerates, the size of which are estimated to be in the range of 100Å.     

Studium der Mosaikstruktur von Kristallen

Zusammenfassung Nach einer neuen Methode wurde der Beflexionsbereich von KCl-Kristallen gemessen. Es wird gezeigt, dass sich die Reflexion der Röntgen-strahlen auch an Mosaikblöcken von KCl der Reflexion am vollkommenen, Kristall nach der Theorie von Darwin und Ewald nähert.     

Abweichungen von der Gleichgewichtsbesetzung der Ar-II-Terme in einem an der Oberfläche von Ferrelektrika erzeugten Plasma

A plasma obtained in argon near the surface of ferroelectric BaTiO₃ ceramics has been examined in this work. It was found that the population densities of the excited Ar II doublet levels are greater than those of the excited Ar II quartet levels. This fact is related to the specific conditions of argon atoms excitation in the electric field of the ferroelectric domains. There is a possibility of ionization with simultaneous excitation of the neutral argon atoms.     

Temperaturverhalten der Exoelektronenemission von Metallen

The emission of exoelectrons by metals after abrasion and after X-ray and neutron irradiation was investigated. The specimens were brought into a heatable counter. With a heating velocity of 2 °C/min the measured glow curves had peaks at 126 °C. This temperature depended only on the velocity of heating, but not on the metal (Al, Cu, Ag, Mo, Rh) or its purity and not on the quenching gas in the counter. To determine activation energies the measured glow curves are compared to calculated ones. There is strong evidence that nonmetallic layers are essential to exoelectron-emission from metals.     

Bestimmung der schalleistung von vielstellenmaschinen

The German standard DIN 45 635 Part 1 describes the determination of sound power level by the envelope measuring method. The method can only be used under certain conditions which arise in a number of industrial measuring tasks. Such conditions do not arise in other tasks of a similar nature. Machines with many similar working positions—e.g. spinning frames—seriously violate one of the conditions. That is, the sound source can be considered approximately as a point source. This can introduce a systematic error of up to 2 dB when the sound power level is determined by the envelope measuring method.In this paper this is proved both theoretically and experimentally. A possibility for correction is given.