JOEL
INTRODUCES : JLED-2
MOST ADVANCED LOW ENERGY ELEC TRON DIFFRACTION APPARATUS (LEED) The J LED-2 is designed to observe the atomic arrangement of surfaces or physical and chemical information on the surface-layers of single crystals. This new apparatus incorporates a specially developed low energy electron gun which has a wide variable accelerating voltage range from 6 eV to 1000 eV. The ion getter and sorption pumps can evacuate the stainless steel diffraction chamber to an order of 10" 10 Torr with minimum contami nation, ensuring accurate and easy observation of surface transport, photoelectric emmission, vapor deposition, and chemical kinetics, as well as the more directly related studies of clean crystal surfaces, adsorption, oxidation, corrosion, epitaxial growth, catalytic process, etc.
Other features: • Unique double screen system: spherical fluorescent screen for direct observation of back-scattered reflection beams, and plane fluorescent screen for forward-scat tered beams permitting the observation of diffraction images at a high accelerating voltage. • T w o repeller grids to obtain clean images at low accel erating voltages with minimized background noises. • Wide specimen movements: 3 6 0 ° rotation, vertical 10 mm, horizontal 5 m m . • Specimen heating temperatures up to 1 2 0 0 ° C by elec tron bombardment system. • Special attachments: Farady cup for current distribu tion measurement; specimen heating; cooling; clearing devices.
Figs 1 and 2 show diffraction images obtained by vapor deposition of A l on Si (111) surface. As shown in Fig. 2, only the super-lattice structure of Si (1 ll)-v"3 χ ν 3 R (30°)-AI appears when applied with the accelerating voltage of 1IV.
JEOL
JAPAN ELECTRON OPTICS LABORATORY CO., LTD. New Tokyo Bldg., 3-2 Marunouchi, Chiyoda-ku, Tokyo, Japan
For additional information, write to your nearest JEOLCO office or Application Center. JEOLCO (U.S.A.), I N C .
JEOLCO (EUROPE) SA
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