Kinetics of chemi-ionization reactions of lanthanide metals (Nd, Sm) from 150 to 450 K
Abstract
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 × 10−10 cm3 s−1 at 300 K and a slight positive temperature dependence. No chemi-ionization of Nd with N2O 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 × 10−12 cm3 s−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.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Nov 23, 2015
- Source ID
- 10.1063/1.4934995
Entities
People
- Albert A Viggiano
- Michael T. Brumbach
- Nicholas S Shuman
- Oscar Martinez Jr.
- Shaun G Ard
Organizations
- Air Force Office of Scientific Research
- Air Force Research Laboratory
- Sandia National Laboratories