Lu Ions Research Articles

Effects of target constituent mass difference on collision cascade induced composition changes in binary alloys

The cascade simulation code MARLOWE has been used to examine low dose composition changes caused by 5 keV Xe ions normally incident on a homogeneous polycrystalline target composed of 50%-50% Lu and Fe. The depth profile of the collision cascade induced atomic concentration of Lu is calculated and yields an excess of Lu in the surface, in agreement with the published results using the code TRIDYN. Calculation of the distributions of recoil Lu and Fe ions originating in particular layers indicate, however, that the heavier mass ion is driven deeper into the target, on the average, than the lighter mass ion—contrary to general perceptions.

XPS study of rare earth dodecaborides: TmB 12, YbB 12 and LuB 12

Single phase TmB 12, YbB 12 and LuB 12 were successfully obtained by the arc-melting and floating zone methods. The XPS measurements of these compounds have indicated that (1) only YbB 12 is a valence fluctuating compound with the valency of +2.9 at room temperature, (2) the correlation energy between Yb 2+ and Yb 3+ ions is about 6.0 eV, (3) Tm and Lu ions in the dodecaborides are in a trivalent state, and (4) the binding energy of the 4f level in TmB 12 and LuB 12 is 5.0 and 7.7 eV, respectively.

Interaction of lanthanide ions with glutamic acid and γ-carboxyglutamic acid

Interactions of lanthanide ions with glutamic acid and γ-carboxyglutamic acid has been studied by the NMR method. These investigations made it possible to determine the coordination mode of aminoacids with lanthanide ions. The results are also of biological interest, since the lanthanides are often used as probes in calcium biochemistry. From our earlier studies on interaction of La(III), Lu(III) and Nd(III) ions with aspartic acid and asparagine it follows that light and heavy lanthanide ions interact in different ways with the carboxylic groups of aminoacids. In order to confirm this suggestion we extended our studies to glutamic acid and γ-carboxyglutamic acid. 1H, 13C NMR and electron spectra were recorded. Correlation of NMR chemical shifts with hypersensitive band intensity changes of lanthanide ions allows the determination of the coordination mode of the discussed aminoacids. Obtained results were confirmed by the Eu(III) luminescence spectra.

Studies in six-co-ordination of the lanthanides with bidentate ligands. The crystal and molecular structures of tris(dicyclohexyldithiophosphinato)dysprosium(III) and tris(dicyclohexyldithiophosphinato)lutecium(III)

The crystal structures of [Dy{P(C6H11)2S2}3] and [Lu{P(C6H11)2S2}3] have been determined from diffractometer data. The co-ordination polyhedra are intermediate between trigonal prismatic and octahedral, the smaller Lu ion having the more octahedral environment. The structures are significantly different from those expected from calculated ligand–ligand repulsions. The origin of this distortion is discussed and compared with that found in analogous praseodymium and samarium compounds. [Dy{P(C6H11)2S2}3] crystallizes in the triclinic space group P, with a= 9.661(2), b= 11.449(2), c= 20.553(3)A, α= 85.88(1), β= 77.32(1), and γ= 84.76(1)°. The R value was 0.042. [Lu{P(C6H11)2S2}3] also crystallizes in the triclinic space group P, with a= 9.659(2), b= 11.399(1), c= 20.532(3)A, α= 85.89(1), β= 77.09(1), and γ= 84.80(1)°. The R value was 0.039.