ЖЭТФ, Том 125,
стр. 1122 (Май 2004)
(Английский перевод - JETP,
Vol. 98, No 5,
доступен on-line на www.springer.com
ON THE HIGH-PRESSURE BEHAVIOR OF THE BOND-BENDING MODE OF AlN
Yakovenko E.V., Gauthier M., Polian A.
Поступила в редакцию: 8 Июля 2003
PACS: 63.20.Dj, 64.70.Kb
Lattice vibrations of the wurtzite-type AlN have been studied by Raman spectroscopy under high pressure up to the phase transition to the rock salt structure at 20 GPa. Five fundamental bands E22, A1(TO), E1(TO), A1(LO), and E1(LO) have a strong, positive pressure shift, whereas the shift of the low-frequency E21 band is weakly positive. We have found that the bond-bending E21 mode has a positive mode Gruneisen parameter γi=0.04, which is qualitatively consistent with the recently reported value γi=0.12 . Thus, we confirm that AlN remains stable with respect to the bond-bending mode, while in most tetrahedral semiconductors bond-bending modes soften on compression. Experimental results are compared with the first-principle calculations.