Accession Number : AD0869846

Title :   Nature of Interatomic Bonding in Beryllium.

Descriptive Note : Final rept. Feb 67-Jan 70,

Corporate Author : MASSACHUSETTS INST OF TECH CAMBRIDGE DEPT OF METALLURGY AND MATERIALS SCIENCE

Personal Author(s) : Averbach, B. L. ; Kaplow, Roy ; Silversmith, Donald J. ; Currat, Roland

Report Date : JAN 1970

Pagination or Media Count : 70

Abstract : The nature of the interatomic bonding in beryllium has been studied by means of elastic constant measurements and observations of Compton scattering from beryllium single crystals. The elastic constants were measured as a function of hydrostatic pressure up to 6 kilobars for pure beryllium and for alloys containing 1.1, 2.4, and 2.9 wt pct copper. The principle result is the observation that the elastic constant C13 approx. = 0. This indicates that acoustic waves normal to the basal plane are completely uncoupled from those travelling in the basal plane, and there is the corresponding implication that there are two orthogonal independent force systems between atoms. Beryllium appears to be a unique metal in this respect. The Compton X-ray scattering profiles were used to obtain the electron momentum distribution. These data were interpreted to indicate that the bonding in beryllium is anisotropic. There is an implication of a covalent bonding contribution along the c-axis, whereas the bonding in the basal plane appears to be metallic. (Author)

Descriptors :   *CHEMICAL BONDS), (*BERYLLIUM, (*BERYLLIUM ALLOYS, CHEMICAL BONDS), COMPTON SCATTERING, ACOUSTIC PROPERTIES, X RAY DIFFRACTION, COPPER ALLOYS.

Subject Categories : Metallurgy and Metallography

Distribution Statement : APPROVED FOR PUBLIC RELEASE