A STATISTICAL THEORY FOR AMORPHOUS STRUCTURES IN METALS,
Abstract
A simple quasi-lattice model is described for highly disorder structures in metals. The basis for the model is, that a given number of atoms N occupies a number of sites N sub t which is greater than N by a factor of 1.5-2.0. The different distinguishable ways in which the atoms can be arranged upon the sites lead to an entropy of disorder. The model is taken first as a crude approximation to the liquid near the melting point. A correspondence is established between the entropy of fusion of the liquid and the preexponential (D sub O) factor in the equation for the coefficient of self-diffusion, derived via the theory of absolute reaction rates. Calculated entropies of fusion and D sub O5 factors are compared with observed values. Application of the approach is then made to the concept of the disordered vacancy or relaxion hypothesized by Nachtreib and Handler. Expressions are derived for the concentration of relaxions and the D sub O factor in the coefficient of self-diffusion for the solid. The value calculated for the entropy of formation of the defect is compared to that inferred from experimental results. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 01, 1963
- Accession Number
- AD0424521
Entities
People
- Charles M. Carlson
Organizations
- Boeing