Praseodymium

About: Praseodymium is a research topic. Over the lifetime, 3287 publications have been published within this topic receiving 39072 citations. The topic is also known as: Pr & element 59.

Atomic Energy Levels - The Rare-Earth Elements. The Spectra of Lanthanum, Cerium, Praseodymium, Neodymium, Promethium, Samarium, Europium, Gadolinium, Terbium, Dysprosium, Holmium, Erbium, Thulium, Ytterbium, and Lutetium,

Abstract: : Energy level data are given for 66 atoms and atomic ions of the 15 elements lanthanum (Z=57) through lutetium (Z=71). These data have been critically compiled from published and unpublished material. Only experimentally determined energy levels are included, the energies being restricted to excitation of outer-shell electrons and to inner-shell excitations up to the soft x-ray range. The levels were taken from analyses of the spectra of atomic gases wherever possible; however, the levels for several of the triply ionized rare earths are from analyses of the spectra of the ions in crystals or solutions. In addition to the level value and the parity, the J value, configuration and term assignments, and the experimental g value are listed wherever available. Leading percentages from the calculated eigenvector are also tabulated for each level if available. The levels are grouped into spectroscopic terms of appropriate coupling schemes where such groups appear meaningful. Ionization potentials are tabulated for most of the spectra. Complete references for the tabulated data are given for each spectrum.

Rare Earth Elements in Soils

Abstract: Rare earth elements (REEs) comprise a group of 17 elements with very similar chemical and physical properties, which include scandium (Sc, Z = 21), yttrium (Y, Z = 39), and the lanthanides with successive atomic numbers (Z from 57 to 71). Lanthanides are the elements lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), and lutetium (Lu). REEs are required in modern industry, and their use in agriculture yielded positive effects in terms of crop yield and body weight of poultry. However, the question of whether the use of REEs in agriculture yields an enrichment of these elements in the environment remains open. It was the aim of this review to summarize the data about REEs in soils with view to their content, fractions, availability, chemical behavior, and translocation in soils and to elucidate further research needs.

Metallic and insulating oxide interfaces controlled by electronic correlations.

Abstract: The formation of two-dimensional electron gases (2DEGs) at complex oxide interfaces is directly influenced by the oxide electronic properties. We investigated how local electron correlations control the 2DEG by inserting a single atomic layer of a rare-earth oxide (RO) [(R is lanthanum (La), praseodymium (Pr), neodymium (Nd), samarium (Sm), or yttrium (Y)] into an epitaxial strontium titanate oxide (SrTiO3) matrix using pulsed-laser deposition with atomic layer control. We find that structures with La, Pr, and Nd ions result in conducting 2DEGs at the inserted layer, whereas the structures with Sm or Y ions are insulating. Our local spectroscopic and theoretical results indicate that the interfacial conductivity is dependent on electronic correlations that decay spatially into the SrTiO3 matrix. Such correlation effects can lead to new functionalities in designed heterostructures.

Phonon-induced relaxation in excited optical states of trivalent praseodymium in laf sub 3.

Abstract: Temperature dependence of linewidths and positions of optical transitions of trivalent praseodymium doped lanthanum fluoride