Accession Number : AD0782191

Title :   Electron Paramagnetic Resonance Study of GaAs Surfaces.

Descriptive Note : Annual rept. no. 8, 1 Feb 73-31 Jan 74,


Personal Author(s) : Haneman,D.

Report Date : APR 1974

Pagination or Media Count : 27

Abstract : The work has been devoted to using electron paramagnetic resonance (EPR) techniques to elucidate the nature of cleaved GaAs surfaces. When suitably covered with cesium and oxygen, they make efficient photoemitters of considerable practical value. An advanced experimental arrangement has been used to cleave specimens in ultra high vacuum (UHV) inside a microwave cavity while connected to a cryoprobe. The EPR signals from single crystals are several orders of magnitude smaller than from crushed powders studied hitherto. Nevertheless sufficient sensitivity has been obtained. The results indicate that oxygen adsorbs at low temperatures to form O2(-) ions with lesser probability than on surfaces of crushed powders. (Modified author abstract)

Descriptors :   *Gallium arsenides, *Electron paramagnetic resonance, *Surfaces, Semiconductors, Photocathodes, Adsorption, Oxygen, Ultrahigh vacuum, Magnetic fields, Single crystals, Australia

Subject Categories : Crystallography

Distribution Statement : APPROVED FOR PUBLIC RELEASE