The electron shuffle: Cerium influences samarium 4f orbital occupancy in heteronuclear Ce-Sm oxide clusters.

Title The electron shuffle: Cerium influences samarium 4f orbital occupancy in heteronuclear Ce-Sm oxide clusters.
Authors J.O. Kafader; J.E. Topolski; V. Marrero-Colon; S.S. Iyengar; C.Chick Jarrold
Journal J Chem Phys
DOI 10.1063/1.4983335
Abstract

The anion photoelectron (PE) spectra along with supporting results of density functional theory (DFT) calculations on SmO(-), SmCeOy(-), and Sm2Oy(-) (y = 1, 2) are reported and compared to previous results on CeO(-) [M. Ray et al., J. Chem. Phys. 142, 064305 (2015)] and Ce2Oy(-) (y = 1, 2) [J. O. Kafader et al., J. Chem. Phys. 145, 154306 (2016)]. Similar to the results on CexOy(-) clusters, the PE spectra of SmO(-), SmCeOy(-), and Sm2Oy(-) (y = 1, 2) all exhibit electronic transitions to the neutral ground state at approximately 1 eV e(-)BE. The Sm centers in SmO and Sm2O2 neutrals can be described with the 4f(5)6s superconfiguration, which is analogous to CeO and Ce2O2 neutrals in which the Ce centers can be described with the 4f 6s superconfiguration (ZCe = ZSm - 4). The Sm center in CeSmO2, in contrast, has a 4f(6) occupancy, while the Ce center maintains the 4f 6s superconfiguration. The less oxidized Sm centers in both Sm2O and SmCeO have 4f(6) 6s occupancies. The 4f(6) subshell occupancy results in relatively weak Sm-O bond strengths. If this extra 4f occupancy also occurs in bulk Sm-doped ceria, it may play a role in the enhanced O(2-) ionic conductivity in Sm-doped ceria. Based on the results of DFT calculations, the heteronuclear Ce-Sm oxides have molecular orbitals that are distinctly localized Sm 4f, Sm 6s, Ce 4f, and Ce 6s orbitals. The relative intensity of two electronic bands in the PE spectrum of Sm2O(-) exhibits an unusual photon energy-dependence, and the PE spectrum of Sm2O2(-) exhibits a photon energy-dependent continuum signal between two electronic transitions. Several explanations, including the high magnetic moment of these suboxide species and the presence of low-lying quasi-bound anion states, are considered.

Citation J.O. Kafader; J.E. Topolski; V. Marrero-Colon; S.S. Iyengar; C.Chick Jarrold.The electron shuffle: Cerium influences samarium 4f orbital occupancy in heteronuclear Ce-Sm oxide clusters.. J Chem Phys. 2017;146(19):194310. doi:10.1063/1.4983335

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58 Ce 140.116000000 Cerium

See more Cerium products. Cerium (atomic symbol: Ce, atomic number: 58) is a Block F, Group 3, Period 6 element with an atomic weight of 140.116. The number of electrons in each of cerium's shells is 2, 8, 18, 19, 9, 2 and its electron configuration is [Xe]4f2 6s2. Cerium Bohr ModelThe cerium atom has a radius of 182.5 pm and a Van der Waals radius of 235 pm. In its elemental form, cerium has a silvery white appearance. Cerium is the most abundant of the rare earth metals. It is characterized chemically by having two valence states, the +3 cerous and +4 ceric states. The ceric state is the only non-trivalent rare earth ion stable in aqueous solutions. Elemental CeriumIt is therefore strongly acidic and oxidizing, in addition to being moderately toxic.The cerous state closely resembles the other trivalent rare earths. Cerium is found in the minerals allanite, bastnasite, hydroxylbastnasite, monazite, rhabdophane, synchysite and zircon. Cerium was discovered by Martin Heinrich Klaproth, Jöns Jakob Berzelius, and Wilhelm Hisinger in 1803 and first isolated by Carl Gustaf Mosander in 1839. The element was named after the asteroid Ceres, which itself was named after the Roman god of agriculture.

Samarium

62 Sm 150.360000000 Samarium

See more Samarium products. Samarium (atomic symbol: Sm, atomic number: 62) is a Block F, Group 3, Period 6 element with an atomic radius of 150.36. Samarium Bohr ModelThe number of electrons in each of samarium's shells is 2, 8, 18, 24, 8, 2 and its electron configuration is [Xe]4f6 6s2. The samarium atom has a radius of 180 pm and a Van der Waals radius of 229 pm. In its elemental form, samarium has a silvery-white appearance. Elemental Samarium PictureSamarium is not found as free element in nature. It is found in the minerals cerite, gadolinite, samarskite, monazite and bastnäsite. Samarium is classified as a rare earth element and is the 40th most abundant element in the Earth's crust. Samarium was discovered and first isolated by Lecoq de Boisbaudran in 1879. It is named after the mineral samarskite, the mineral from which it was isolated.

Related Forms & Applications

Oxides
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