Accession Number : AD0610780

Title :   CATALYTIC PROPERTIES OF SEMICONDUCTORS.

Descriptive Note : Final rept. for 1 Jul 58-30 Sep 63,

Corporate Author : POLYTECHNIC INST OF BROOKLYN N Y

Personal Author(s) : Banks,E. ; Collins,F. C. ; Loebl,E. M. ; Sarfati,I.

Report Date : 30 SEP 1963

Pagination or Media Count : 85

Abstract : A study of the catalytic activity of semiconductor surfaces is reported. The ortho-parahydrogen conversion and hydrogen-deuterium exchange were investigated on the following materials: sodium tungsten bronzes, (Na)x WO3 0.30<x<0.98, graphite-like ytterbium disilicide, YbSi2, germanium, from p-type, resistivity 0.01 ohm cm to n-type 0.005 ohm cm and gallium arsenide from p-type, 0.003 ohm cm to n-type, ca. 0.001 ohm cm. The first two materials were in the form of crystalline powders while the germanium and gallium arsenide were obtained in the form of single-crystal wafers and the catalytic surface was generated by crushing under 'clean' conditions (high vacuum). In this case catalytic activity was measured during the period of crushing at room temperature, and thereafter at temperatures 373-550K and hydrogen pressures 6-100 mm Hg. For germanium the activity was also measured at temperatures up to 700K. Some measurements were also made under ultra-high vacuum conditions. The activity of the sodium tungsten bronzes was measured from 77 to 470K (pressure 10-400 mm Hg) ytterbium disilicide was measured in the temperature range 50-400K.

Descriptors :   (*SEMICONDUCTORS, CATALYSTS), (*CATALYSIS, REACTION KINETICS), (*SODIUM COMPOUNDS, TUNGSTATES), (*GALLIUM ALLOYS, ARSENIC ALLOYS), (*YTTERBIUM COMPOUNDS, SILICIDES), (*GERMANIUM, CATALYSIS), INTERNAL CONVERSION, EXCHANGE REACTIONS, HEAT OF ACTIVATION, THERMODYNAMICS, DEUTERIUM, POWDERS, SURFACES, HYDROGEN

Distribution Statement : APPROVED FOR PUBLIC RELEASE