Accession Number:

ADA073278

Title:

Interactions of Molecular and Ion Beams With Surfaces.

Descriptive Note:

Rept. no. 1 (Final) 1 Jan 77-31 May 79,

Corporate Author:

HOUSTON UNIV TX DEPT OF CHEMISTRY

Personal Author(s):

Report Date:

1979-06-21

Pagination or Media Count:

27.0

Abstract:

Low kinetic energy active ion bombardment of transition metals, Si, Ge, Sn, Pb, graphite, and diamond have shown that chemical reactions can be induced between ion beams and surfaces. These reactions are specific and selective with respect to the ion-target combination and the thickness of the reacted layer can be controlled by varying the ion energy. The techniques of x-ray and UV photoelectron spectroscopy, Auger spectroscopy, secondary ion mass spectrometry SIMS and thermal desorption spectrometry TDS under ultra-high vacuum conditions are used to characterize the products of the beam-surface reactions. The reaction of 30-3000 eV nitrogen beams with the first-row transition metals results in the formation of metal nitrides. The amount of nitrogen reacting with the metal can be correlated to the enthalpy of formation of the metal nitride. Reactions of nitrogen with M, MO, and MO2 M Si, Ge, Sn, Pb produces nitrides with no evidence for nitrate, nitrite, or nitroso formation in the oxides. A mechanism is proposed for the reaction which involves charge exchange neutralization and dissociation of the ion at the surface followed by penetration into the lattice, thermalization, and finally chemical reaction.

Subject Categories:

  • Industrial Chemistry and Chemical Processing
  • Atomic and Molecular Physics and Spectroscopy
  • Nuclear Physics and Elementary Particle Physics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE