THE EFFECT OF CHEMICAL COMBINATION ON K X-RAY EMISSION SPECTRA FROM MAGNESIUM, ALUMINUM AND SILICON.
Summary rept. for Oct 63-Oct 64,
AIR FORCE MATERIALS LAB WRIGHT-PATTERSON AFB OHIO
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Wavelength and intensities are reported for the K series of Mg, Al, and Si using primary excitation. Spectra are shown and line positions and intensities are detailed using both metal and oxide as the X-ray source. Significant differences are seen between metal and oxide spectra especially in wavelength and shape of K-beta and large changes are noted in the intensities of some satellite lines. Spectra from a number of aluminum intermetallic compounds are discussed including line positions, satellite line ratios and line shape. It is shown that the spectra fall into three predictable groups, for example, good conductors, poorer conductors, semiconductors and insulators. Structurally similar compounds give similar spectra. For instance, line positions, shapes and intensities are nearly identical for NbAL3 and TaAl3. It is not possible to correlate spectra with aluminum coordination number and previous work using K-alpha where secondary excitation was used could not be reproduced using primary excitation. Possible reasons for this disagreement are discussed. K-beta from both solid and molten aluminum is shown and a theory of structure in liquid metals is discussed based on changes observed between solid and liquid spectra. Data for a series of silicon compounds are shown and the results compared to aluminum. Silicon compounds did not fall into predictable groups as did aluminum compounds, showing the differing bonding and electron sharing between aluminum and silicon. Author