Accession Number : AD0612297

Title :   RADIAL DISTRIBUTION FUNCTIONS IN SOLID COBALT.

Descriptive Note : Master's thesis,

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

Personal Author(s) : Lagneborg,Rune Gunnar ; Kaplow,Roy

Report Date : 23 DEC 1964

Pagination or Media Count : 48

Abstract : Radial distribution functions have been calculated from x-ray diffraction data by means of digital computer programs for Co-alpha (h.c.p.) annnd Co-beta (f.c.c.) near the allotropic transformation temperature. These functions provide values of lattice parameters, mean square amplitudes of vibration, vibrational coupling factors, and the mean force potential function. The mean square amplitude of vibration u-2s for alpha and beta at 417C are 0.0155 sq A and 0.0168sq A, which correspond to Debye temperatures of 332K and 320K, respectively. The Debye temperature and coupling factors obtained for beta at 417C were consistent with a second experimental distribution function determined at 678C, indicating that those parameters are essentially invariant over that range of temperature. From the mean force potential functions the elastic modulii for nearest neighbor directions have been determined. In both alpha-and beta-phase the measured value is approximately 2.1 x 10 to the 12th power dynes/sq cm. The difference between the nearest neighbor potential minima in the alpha- and beta-phases at 417C is 100 cal/gram atom. (Author)

Descriptors :   (*COBALT, CRYSTAL LATTICES), (*CRYSTAL LATTICES, COBALT), (*PHASE STUDIES, COBALT), SOLIDS, X RAY DIFFRACTION, STATISTICAL FUNCTIONS, VIBRATION, CRYSTALLOGRAPHY, TRANSITION TEMPERATURE, ATOMIC PROPERTIES, THERMODYNAMICS, ELASTIC PROPERTIES

Distribution Statement : APPROVED FOR PUBLIC RELEASE