We have studied cubic boron arsenide (BAs) by Raman spectroscopy and first-principles simulations. The Raman T2 phonon involving B vibrations in natBAs shows a complex isotope two-mode behavior, not seen before in isotopically disordered materials. The majority isotope 11B phonon at 704 cm-1 obeys average isotopic mass dependence and mass disorder renormalization, whereas a band at 723 cm-1 stems from predominately 10B vibrations in natBAs. The observed lack of T2 LO-TO splitting in both natBAs and 11BAs and third- and fourth-order anharmonicity contributions compensating each other in the temperature dependence of the T2 phonon are among the other curious vibrational properties of BAs.
|期刊||Physical Review B - Condensed Matter and Materials Physics|
|出版狀態||Published - 2014 1月 28|
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