Stability and Properties of Compositionally Modulated Films.
HARVARD UNIV CAMBRIDGE MA DIV OF APPLIED SCIENCES
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The thermodynamics and kinetics governing the stability of compositionally modulated materials are reviewed. Typical results of experiments on fcc and amorphous metals are presented to demonstrate the effects of interdiffusion. Two coarsening mechanisms are analyzed, as is the stability of orthogonal waves in phase separating systems. The interdiffusivity between amorphous Si and Ge in the temperature range 550-630K is 1.07x10 to the minus 10th power exp-1.6 evkTm2 1s, for a modulation wavelength of 5.83 nm. No crystallization occurred during the anneals. The theories for the enhancement of the elastic modulus in crystalline compositionally modulated films are reviewed. Both the Fermi sphere-Brillouin zone interaction model and the coherency stress model are found to be inadequate and insufficiently developed. Author
- Solid State Physics