Nanoscale analysis of the oxidation state and surface termination of praseodymium oxide ultrathin films on ruthenium(0001).

Title Nanoscale analysis of the oxidation state and surface termination of praseodymium oxide ultrathin films on ruthenium(0001).
Authors J.I. Flege; J.O. Krisponeit; J. Höcker; M. Hoppe; Y. Niu; A. Zakharov; A. Schaefer; J. Falta; E.E. Krasovskii
Journal Ultramicroscopy
DOI 10.1016/j.ultramic.2017.05.007
Abstract

The complex structure and morphology of ultrathin praseodymia films deposited on a ruthenium(0001) single crystal substrate by reactive molecular beam epitaxy is analyzed by intensity-voltage low-energy electron microscopy in combination with theoretical calculations within an ab initio scattering theory. A rich coexistence of various nanoscale crystalline surface structures is identified for the as-grown samples, notably comprising two distinct oxygen-terminated hexagonal Pr2O3(0001) surface phases as well as a cubic Pr2O3(111) and a fluorite PrO2(111) surface component. Furthermore, scattering theory reveals a striking similarity between the electron reflectivity spectra of praseodymia and ceria due to very efficient screening of the nuclear charge by the extra 4f electron in the former case.

Citation J.I. Flege; J.O. Krisponeit; J. Höcker; M. Hoppe; Y. Niu; A. Zakharov; A. Schaefer; J. Falta; E.E. Krasovskii.Nanoscale analysis of the oxidation state and surface termination of praseodymium oxide ultrathin films on ruthenium(0001).. Ultramicroscopy. 2017;183:6166. doi:10.1016/j.ultramic.2017.05.007

Related Elements

Praseodymium

See more Praseodymium products. Praseodymium (atomic symbol: Pr, atomic number: 59) is a Block F, Group 3, Period 6 element with an atomic weight of 140.90765. Praseodymium Bohr Model The number of electrons in each of praseodymium's shells is 2, 8, 18, 21, 8, 2 and its electron configuration is [Xe]4f3 6s2. The praseodymium atom has a radius of 182 pm and a Van der Waals radius of 239 pm. Praseodymium resembles the typical trivalent rare earths, however, it will exhibit a +4 state when stabilized in a zirconia host. Elemental PraseodymiumUnlike other rare-earth metals, which show antiferromagnetic and / or ferromagnetic ordering at low temperatures, praseodymium is paramagnetic at any temperature above 1 K. Praseodymium is found in the minerals monazite and bastnasite. Praseodymium was discovered by Carl Auer von Welsbach in 1885. The origin of the element name comes from the Greek words prasios didymos, meaning green twin.

Ruthenium

See more Ruthenium products. Ruthenium (atomic symbol: Ru, atomic number: 44) is a Block D, Group 8, Period 5 element with an atomic weight of 101.07. Ruthenium Bohr ModelThe number of electrons in each of ruthenium's shells is [2, 8, 18, 15, 1] and its electron configuration is [Kr] 4d7 5s1. The ruthenium atom has a radius of 134 pm and a Van der Waals radius of 207 pm. Ruthenium was discovered by Jędrzej Śniadecki in 1807. It was first recognized as a distinct element by Karl Ernst Claus in 1844. Elemental RutheniumIn its elemental form, ruthenium has a silvery white metallic appearance. Ruthenium is a rare transition metal belonging to the platinum group of metals. It is found in pentlandite, pyroxenite, and platinum group metal ores. The name Ruthenium originates from the Latin word "Ruthenia," meaning Russia.

Related Forms & Applications