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Title: Kinetics of chemi-ionization reactions of lanthanide metals (Nd, Sm) from 150 to 450 K

The kinetics of chemi-ionization reactions of neodymium and samarium atoms with an oxygen atom to yield a metal monoxide cation and electron were studied using a flow tube apparatus over a temperature range of 150–450 K. Nd reacts efficiently with O, near the hard-sphere collision limit at all temperatures, with a rate constant of 3 × 10{sup −10} cm{sup 3} s{sup −1} at 300 K and a slight positive temperature dependence. No chemi-ionization of Nd with N{sub 2}O was observed, despite the reaction being exothermic. Chemi-ionization of Sm with O is slow, with a rate constant at 300 K determined to be 7 × 10{sup −12} cm{sup 3} s{sup −1}, although with large uncertainty. The Sm reaction also shows a slightly positive temperature dependence, described by a small activation energy of 60 meV. Although not definitive, the data suggest that excited states of Sm react efficiently whereas ground state Sm reacts inefficiently.
Authors:
; ; ;  [1] ;  [2]
  1. Air Force Research Laboratory, Space Vehicles Directorate, Kirtland Air Force Base, New Mexico 87117 (United States)
  2. Sandia National Laboratories, P.O. Box 5800, Albuquerque, New Mexico 87185 (United States)
Publication Date:
OSTI Identifier:
22493271
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Chemical Physics; Journal Volume: 143; Journal Issue: 20; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; ACTIVATION ENERGY; ATOMS; CATIONS; CHEMICAL REACTIONS; ELECTRONS; EXCITED STATES; GROUND STATES; NEODYMIUM; NITROUS OXIDE; OXYGEN; REACTION KINETICS; SAMARIUM; TEMPERATURE DEPENDENCE