Results 1 - 10 of 34
Results 1 - 10 of 34. Search took: 0.017 seconds
|Sort by: date | relevance|
[en] A pseudo-curved neutron monochromator with a continuously variable curvature was constructed with four flat pieces of oriented pyrolytic graphite (OPG). Curvatures which yield maximum diffracted intensities were determined for neutrons of wavelengths 1 A and 2.4 A. The increase of the intensity relatively to that of a flat monochromator is by a factor of 2 and 1.5, for 1 A and 2.4 A, respectively. The neutron flux at three positions along the neutron path was determined by gold foils activation and compared with the flux from flat monochromators of OPG and copper
[en] Polycrystalline samples of UCoNiSi2 and UNiCuSi2 have been studied by X-ray diffraction at 295 K and ac susceptibility at 80-295 K. They have a ThCr2Si2-type crystallographic structure and order magnetically. UCoNiSi2 undergoes an antiferromagnetic transition at 115 K. UNiCuSi2 undergoes three transitions at 162, 122 and 102 K to antiferromagnetic and ferro/ferrimagnetic phases. (orig.)
[en] The U(M,M')2X2 solid solutions (M, M' = Co, Ni, Cu ; X = Si, Ge), crystallizing in the body-centered tetragonal ThCr2Si2-type structure, were studied intensively by neutron diffraction at the NRCN since 1988, and their magnetic phase diagrams were established. Although several of these magnetic phase diagrams were studied also by AC-susceptibility measurements, the U(Col-xCux)2Ge2 system was studied by neutron diffraction only. The originally established magnetic phase diagram of the latter system involved only materials with x = 0, 0.25, 0.50, 0.75, and 1. The more recently published version of the diagram involved also the compositions x = 0.60 and 0.70. In this paper we report our recent AC-susceptibility and SQUID-magnetization complementary measurements on all available solid solutions in this system
[en] The crystallographic and electronic structure of UFe2Al10 was studied as a function of pressure by combining X-ray diffraction results with the full potential linearized augmented plane wave (LAPW) calculations method. The volume-pressure reduction measured at 23.5 GPa is V/V0 = 0.87, with a B0 value of 132 ± 8 GPa. The uranium 5f electrons in this compound are located in a narrow and well-defined band above EFermi, having a very weak interaction with the iron 3d band located below EFermi. Consequently, the DOS at EFermi is close to zero, indicating a close to zero-magnetic moment of the uranium atom at low temperature up to a pressure of 23.5 GPa, as expected from the layered crystallographic structure of this compound. The above assumption is supported by preliminary neutron diffraction data, where no long-range magnetic order was detected down to 3 K.