Construction of a surface positronium lifetime spectroscopy apparatus with a spin-polarized low energy positron beam

ABSTRACTIn-situ recording of ultra-thin film growth by Low Energy Electron Microscopy (LEEM) results in accurate determinations of monolayer metal deposition rates for difficult to calibrate deposition geometries. Deposition rates and growth features were determined for Cu and Co on W (110) allowing for thickness control at the submonolayer level. Also, the transparencies of non-Magnetic overlayers of Pd (111) and Cu (111) to very low energy spin polarized electrons were compared and qualitatively explained by band structure considerations. Cu (111) is much more transparent than Pd (111) so that magnetic domain structures can be observed through at least 4 nmof Cu (111). This suggests the use of Cu (111) and other metals of suitable band structure as protective layers for surface magnetic studies.

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Analysis of Magnetic and Non-Magnetic Surfaces by Spin-Polarized Low-Energy Electron Diffraction

Physica Scripta ◽

10.1088/0031-8949/1983/t4/008 ◽

1983 ◽

Vol T4 ◽

pp. 47-51 ◽

Cited By ~ 7

Author(s):

Roland Feder

Keyword(s):

Electron Diffraction ◽

Low Energy ◽

Energy Electron ◽

Low Energy Electron Diffraction ◽

Magnetic Surfaces ◽

Spin Polarized ◽

Low Energy Electron

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Defect Formation by Ion Implantation in Cz-Si Studied by a Monoenergetic Positron Beam

MRS Proceedings ◽

10.1557/proc-262-1061 ◽

1992 ◽

Vol 262 ◽

Author(s):

A. Uedono ◽

Y. Ujihira ◽

L. Wei ◽

Y. Tabuki ◽

S. Tanigawa ◽

...

Keyword(s):

Oxygen Vacancy ◽

Ion Implantation ◽

Defect Formation ◽

Positron Beam ◽

Low Energy ◽

Doppler Broadening ◽

Positron Energy ◽

Annealing Experiments ◽

Incident Positron ◽

Ion Implanted

ABSTRACTVacancy-type defects in ion implanted Si were studied by a monoenergetic positron beam. The depth-distributions of the defects were obtained from measurements of Doppler broadening profiles of the positron annihilation as a function of incident positron energy. The results showed that a size of vacany-clusters introduced by 150-keV P+-ion implantation was found to be smaller than that introduced by 2-MeV P+-ion implantation. This was attributed to an overlap of collision cascades in low-energy (150 keV) ion implanted specimens. From isochronal annealing experiments for 80-keV B+- and 150-keV P+-ion implanted specimens, the defected region was removed by 1200 °C annealing, however, for 2-MeV P+-implanted specimen, two-types of oxygen-vacancy complexes were found to coexist even after 1200 °C annealing.

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