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.