Crystal growth of some rare earth and uranium intermetallics from the melt

Domain Observation Techniques

A theoretical study has been made of the defect structure of calcium sulphide. Empirical interatomic potentials are obtained from the analysis of crystal data for calcium and sodium sulphides. Defect energies are calculated using the Harwell HADES program which is based on a generalized Mott—Littleton method. The results predict the dominance of Schottky disorder in the crystal. The activation energy for the migration of both anions and cations is calculated. The results are in good agreement with the experimental data, suggesting that vacancy migration predominates. The results show that the ionic model works for sulphides, and its application to other chalcogenide systems is discussed.

Study of defect structure of calcium sulphide

Domain structure observed by means of the Kerr effect and oxygen cryocondensation methods in a U3P4 crystal

Anisotropy behaviour of U 3 As 4

Magnetic domain patterns observed at 150 K on (110) and (211) surfaces of a U3As4 single crystal using a low temperature colloid technique are described.



Magnetische Bereichsstrukturen bei 150 K an den (110)- und (211)-Oberflachen eines U3As4-Einkristalles werden mit Hilfe der Tieftemperatur-Bitter-Technik beobachtet.

P. Novotný

Papers

Bitter figure observations on U3As4 at low temperatures