Abstract
The results of polarized Raman scattering, far-infrared (FIR) absorption, Kramers-Kronig analysis of FIR reflectance, and lattice-dynamical calculations of the perovskitelike compound (space group P4mm) are reported. All 16 Raman- and infrared-active Γ-point phonons (6+2+8E) have been identified and assigned to definite atomic vibrations in close comparison with the structurally similar tetragonal system. The appearance of an additional strong Raman line at 576 is discussed in terms of disorder-induced Raman scattering. The normal-mode frequencies are in reasonable agreement with the results of lattice-dynamical calculations in the framework of a shell model with parameters extracted from several metallic oxides and perovskite compounds.
- Received 29 December 1992
DOI:https://doi.org/10.1103/PhysRevB.47.15201
©1993 American Physical Society