Superheavy Element Flerovium (Element 114) Is a Volatile MetalAccess to the published version may require subscription. Superheavy Element Flerovium (Element 114) is a Volatile MetalAlexander Yakushev †, , Jacklyn M. ABSTRACT: The electron shell structure of superheavy elements, i.e., elements with atomic number Z ≥ 104, is influenced by strong relativistic effects caused by the high Z. Early atomic calculations on element 112 (copernicium, Cn) and element 114 (flerovium, Fl) having closed and quasiclosed electron shell configurations of 6d 10 7s 2 and 6d 10 7s 2 7p 1/2 , respectively, predicted them to be noble gas-like due to very strong relativistic effects on the 7s and 7p 1/2 valence orbitals. Recent fully relativistic calculations studying Cn and Fl in different environments suggest them to be less reactive compared to their lighter homologs in the groups, but still exhibiting a metallic character. Experimental gassolid chromatography studies on Cn have, indeed, revealed a metal-metal bond formation with Au. In contrast to this, for Fl, the formation of a weak bond upon physisorption on a Au surface was inferred from first experiments. Here, we report on a gas-solid chromatography study of the adsorption of Fl on a Au surface. Fl was produced in the nuclear fusion reaction 244 Pu( 48 Ca, 3-4n) 288,289 Fl and was isolated in-flight from the primary 48 Ca beam in a physical recoil separator. The adsorption behavior of Fl, its nuclear α-decay product Cn, their lighter homologs in groups 14 and 12, i.e., Pb and Hg, and the noble gas Rn were studied simultaneously by isothermal gas chromatography and thermochromatography. Two Fl atoms were detected. They adsorbed on a Au surface at room temperature in the first, isothermal part, but not as readily as Pb and Hg. The observed adsorption behavior of Fl points to a higher inertness compared to its nearest homolog in the group, Pb. However, the measured lower limit for the adsorption enthalpy of Fl on a Au surface points to the formation of a metal-metal bond of Fl with Au. Fl is the least reactive element in the group, but still a metal.

Experiments with the new recoil separator, TASCA, at the GSI were performed using beams of 48 Ca to irradiate targets of [206][207][208] Pb leading to the production of [252][253][254]

Carbonyl complexes of radioactive transition metals can be easily synthesized with high yields by stopping nuclear fission or fusion products in a gas volume containing CO. Here, we focus on Mo, W, and Os complexes. The reaction takes place at pressures of around 1 bar at room temperature, i.e., at conditions that are easy to accommodate. The formed complexes are highly volatile. They can thus be transported within a gas stream without major losses to setups for their further investigation or direct use. The rapid synthesis holds promise for radiochemical purposes and will be useful for studying, e.g., chemical properties of superheavy elements.

H. RUPPERSBERG et al. : Non-Linear Surface-Stress Fields o,,(z) and uyy(z) 68 1 phys. stat. sol. (a) 116, 681 (1989) Subject classification: 62.20 and 68.25; S1.2 For single-phase polycrystalline materials the relation is discussed between the elastic strain ~( y , p) obtained from X-ray diffract'ion experiments and the polynomial expansion of the stress components oJo) and O~+ Q O ( Z ) with respect to the distance z from the external surface of the specimen. -1 universal plot is proposed for F(y, to, (hkl)) = +(c(p) + ~( p + 90)) curves measured for different penetration depths t o of the radiation and for different reflecting lattice planes. This expression also allows absolute scaling of the E values. The formalism is applied for discussing s(y, p, to, (hkl)) curves obtained with synchrotron radiation from a cold-rolled nickel plate. They indicate strongly non-linear variations of stress in a surface layer about two pm thick. F u r einphasige vielkristalline Werkstoffe wird der Zusammenhang zwischen rontgenographisch ermittelten Dehnungen ~( y , p) und den nach dem Xbstand z von der Grenzflache in Reihe entwikkelten Spannungskomponenten oB(z) und O~+ Q O ( Z ) erortert. Es wird eine universelle Auftragung fur E(y, to, (hkl)) = -;-(e(p) + ~( p + 90))-Kurven vorgeschlagen, die fur beliebige Eindringtiefen t o und reflektierende Netzebenen ermittelt werden. Es ergibt sich daraus auch die Moglichkeit, E absolut zu bestimmen. Der Formalismus wird auf c ( y , p, to, (hk2))-Kurven angewendet, die mittels Synchrotronstrahlung fur ein kaltgewalztes Pu'ickelblech erhalten wurden. Es ergeben sich stark nichtlineare Spannungsanderungen in einer etwa 2 pm dicker, Oberflachenschicht.

Abstract:We report on the in-situ synthesis of metal carbonyl complexes with short-lived isotopes of transition metals. Complexes of molybdenum, technetium, ruthenium and rhodium were synthesized by thermalisation of products of neutron-induced fission of 249 Cf in a carbon monoxide-nitrogen mixture. Complexes of tungsten, rhenium, osmium, and iridium were synthesized by thermalizing short-lived isotopes produced in 24 Mg-induced fusion evaporation reactions in a carbon monoxide containing atmosphere. The chemical reactions took place at ambient temperature and pressure conditions. The complexes were rapidly transported in a gas stream to collection setups or gas phase chromatography devices. was studied. We also studied the stability of some of the complexes, showing that these start to decompose at temperatures above 300 ∘ C in contact with a quartz surface.Our studies lay a basis for the investigation of such complexes with transactinides.