Interactions of ion beams with surfaces: Dynamics of the reaction of N/sub 2//sup +/ with rhenium

Journal Article · Sun Jun 01 04:00:00 EDT 1980 · J. Chem. Phys.; (United States)

OSTI ID:5338392

Hu, H; Fukuda, Y; Baldwin, D A; Murray, P T; Rabalais, J W

Reactions of N/sub 2//sup +/ ion beams with the surface of polycrystalline rhenium foil over the range 150--3 000 eV have been studied by the techniques of x-ray photoelectron spectroscopy (XPS) and thermal desorption spectrometry (TDS). The reactions produce a nitride layer of the type ReN/sub x/, 0.21< or =x< or =0.40, with x varying as a function of ion kinetic energy and depth into the surface. The nitride layer extends from the surface down to the penetration depth of the atoms, which varies from approx.15 A at 0.3 keV to approx.76 A at 2.5 keV ion energy. The product nitride and chemisorbed nitrogen on Re are distinctly different, exhibiting N/sub 1s/ binding energies of 397.9 and 396.8 eV, respectively, and TDS maxima near 425 and 600 /sup 0/C, respectively. The value of x in ReN/sub x/ increases linearly with the nitrogen ion flux and reaches a steady state condition at a dose of 9.5 x 10/sup 16/ ions/cm/sup 2/ which is determined by the opposing rate of nitride formation and the sputtering rate by impinging N/sub 2//sup +/ ions. An expression describing the rate of nitration as a function of the reaction cross section sigma/sub r/ and the sputtering cross section sigma/sub s/ is derived. The simplified expressions for the limiting cases of initial rates (t..-->..0) and the steady state (t..-->..infinity) product concentration, which are used to interpret the experimental results, yield sigma/sub r/approx. =3 x 10/sup -18/ cm/sup 2/ for the N/sub 2//sup +/+Re(metal)..-->..ReN/sub x/ reaction at an ion impact energy of 500 eV.

• Research Organization: Department of Chemistry, University of Houston, Houston, Texas 77004
• OSTI ID: 5338392
• Journal Information: J. Chem. Phys.; (United States), Journal Name: J. Chem. Phys.; (United States) Vol. 72:11; ISSN JCPSA
• Country of Publication: United States
• Language: English

Related Subjects

640301* -- Atomic
Molecular &amp; Chemical Physics-- Beams &amp; their Reactions
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
BEAMS
CHARGED PARTICLES
CHEMICAL REACTIONS
COLLISIONS
ELECTRON SPECTROSCOPY
ELEMENTS
ENERGY RANGE
EV RANGE
EV RANGE 100-1000
ION BEAMS
ION COLLISIONS
IONS
KEV RANGE
KEV RANGE 01-10
METALS
MOLECULAR IONS
NITROGEN IONS
PHOTOELECTRON SPECTROSCOPY
REFRACTORY METALS
RHENIUM
SPECTROSCOPY
TRANSITION ELEMENTS