Accession Number : AD0612284

Title :   APPLICATION OF DIFFERENTIAL SPECTROPHOTOMETRY TO THE STOICHIOMETRY OF ELECTRONIC MATERIALS.

Descriptive Note : Final rept. 1 May 62-14 Dec 64,

Corporate Author : REPUBLIC AVIATION CORP FARMINGDALE N Y

Personal Author(s) : KELLY,R. S. ; Eldridge,A. ; Lanning,E. W. ; Bastian,R.

Report Date : 14 MAR 1965

Pagination or Media Count : 85

Abstract : Spectrophotometric methods for the analysis of gallium arsenide and bismuth telluride for their major elements, with a precision suitable for stoichiometry studies are developed. Utilizing the EDTA complex, bismuth is determined by direct differential spectrophotometry with a precision (standard deviation) of better than one part per thousand of the amount present. Arsenic, tellurium, and gallium are determined by the technique of indirect spectrophotometry, with a precision in the low parts per ten thousand range. Potassium dichromate is used as the reagent for arsenic and tellurium; gallium is determined by EDTA in the presence of copper. Analyses are presented on synthetic and actual samples of the compounds, including total analyses of gallium arsenide prepared under various arsenic pressures. Some gallium arsenide samples are very close to theoretical in composition, while one sample made under excess arsenic pressure shows an excess of this element in the main body of the ingot. Segregation of the elements in the tail sections of the ingots is evident. Republic suggests that methods for the analysis of gallium arsenide be utilized to see if a correlation can be established between major composition and electronic properties such as laser action. The technique of indirect precision spectrophotometry should also be applied to other electronic material systems. (Author)

Descriptors :   (*SPECTROPHOTOMETERS, CHEMICAL ANALYSIS), (*CHEMICAL ANALYSIS, SPECTROPHOTOMETERS), GALLIUM COMPOUNDS, ARSENIDES, BISMUTH COMPOUNDS, TELLURIDES, POTASSIUM COMPOUNDS, CHROMATES, ELECTRICAL PROPERTIES, ELECTRONICS, MATERIALS, PHYSICAL CHEMISTRY, LASERS

Distribution Statement : APPROVED FOR PUBLIC RELEASE