Raman Spectroscopic Study of the Optical Phonons of Mg 2 Si 1- x Sn x Solid Solutions
Abstract
Mg2Si1−xSnx solid solutions are prepared in the composition range from x = 0 to 1 by mechanical alloying using high‑energy ball milling followed by direct‑current sintering at 600–800 °C. X‑ray diffraction analysis confirms that the samples obtained are uniform solid solutions. Raman spectroscopy shows two first‑order phonon Raman bands and a distribution of Raman signals due to second‑order phonon Raman scattering. The first‑order Raman bands are assigned to the nondegenerate Raman‑forbidden F1u (LO) mode and the triply degenerate Raman‑allowed F2g mode. Both modes exhibit a linear shift of the phonon frequency with a composition showing a clear one‑mode behavior for this solid solution. The findings are discussed in the context of existing theories for the occurrence of the one‑mode or two‑mode behavior of phonons in solid solutions.
- Publication:
-
Physica Status Solidi Rapid Research Letters
- Pub Date:
- March 2020
- DOI:
- 10.1002/pssr.201900574
- Bibcode:
- 2020PSSRR..1400574Y