Kinetics of chemi-ionization reactions of lanthanide metals (Nd, Sm) from 150 to 450 K
- Air Force Research Laboratory, Space Vehicles Directorate, Kirtland Air Force Base, New Mexico 87117 (United States)
- Sandia National Laboratories, P.O. Box 5800, Albuquerque, New Mexico 87185 (United States)
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.
- OSTI ID:
- 22493271
- Journal Information:
- Journal of Chemical Physics, Vol. 143, Issue 20; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0021-9606
- Country of Publication:
- United States
- Language:
- English
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