The temperature dependence of the lattice parameter of Ge1-y Sny alloys deposited on Si substrates has been determined from an analysis of their x-ray reciprocal-space maps. It is found that over the range 0<y<0.03 the alloy thermal expansivity increases by up to 20% as a function of y. This implies a strong deviation from a linear interpolation between the end compounds since the thermal expansivities of pure Ge and α-Sn are nearly the same. Alternative interpolation formulas based on a Debye model and a mixed Debye-Einstein model of the phonon structure are tested and it is found that they also fail to explain the observed increase in thermal expansivity.
|Original language||English (US)|
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|State||Published - Jun 29 2010|
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics