Electron-spin-polarization effects in low-energy electron diffraction, ion neutralization, and metastable atom deexcitation at solid surfaces. Progress report No. 2, January 1, 1982-December 31, 1982
The use of electron spin polarization measurements in conjunction with LEED can provide information concerning surface geometrical structure over and above that obtainable by conventional LEED intensity measurements. During the present contract year a comprehensive polarized LEED study of Ni(001) and Ni(001)c(2x2)Te surfaces has been completed. The large polarization features evident in the Ni data indicate that polarization measurements can be applied to surface studies involving samples of low atomic number, and the marked changes evident upon deposition of a c(2x2)Te adlayer point up the sensitivity of polarization to the presence of adsorbates. Further, preliminary relativistic dynamical calculations indicate that adsorbate-substrate systems can be successfully handled theoretically. A GaAs spin-polarized electron source has been constructed and is undergoing testing. This source will provide improved accuracy and data acquisition rates in future polarized LEED studies. A preliminary study suggests that clean Ni(001) surfaces can be successfully prepared by ion bombardment and laser annealing. A project is also underway to utilize spin polarization measurements in conjunction with ion neutralization spectroscopy (INS) and metastable deexcitation spectroscopy (MDS) to provide new information on surface electronic structure and to elucidate the dynamical processes underlying these spectroscopies. Diagnostics on the polarized He/sup +/ ion source were undertaken using 1.08 ..mu..m radiation provided by a tunable NaF (F/sup +//sub 2/)* color-center laser. Also, use of this laser to optically pump the He(2/sup 3/S) atomic beam resulted in polarizations of approx. 70%. MDS studies of Ni(110) surface magnetism are underway using a Ni crystal magnetised along the easy (1 anti 11) direction.
- Research Organization:
- Rice Univ., Houston, TX (USA). Dept. of Physics
- DOE Contract Number:
- AS05-81ER10817
- OSTI ID:
- 7062868
- Report Number(s):
- DOE/ER/10817-2; ON: DE83001860
- Country of Publication:
- United States
- Language:
- English
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Electron spin polarization effects in low energy electron diffraction, ion neutralization and metastable atom deexcitation at solid surfaces. Progress report No. 4, 1 January-31 December 1984
Electron spin polarization effects in low-energy electron diffraction, ion neutralization, and metastable-atom deexcitation at solid surfaces. Progress report No. 3, January 1-December 31, 1983
Related Subjects
GENERAL PHYSICS
ELECTRON DIFFRACTION
SPIN ORIENTATION
ION SCATTERING ANALYSIS
CRYSTAL LATTICES
CRYSTAL STRUCTURE
RESEARCH PROGRAMS
SPUTTERING
SURFACES
CHEMICAL ANALYSIS
COHERENT SCATTERING
DIFFRACTION
NONDESTRUCTIVE ANALYSIS
ORIENTATION
SCATTERING
640301* - Atomic
Molecular & Chemical Physics- Beams & their Reactions