2002/07/31 by M. N. Iliev, M. V. Abrashev, V. N. Popov +2
Materials Science · Physics and Astronomy · #Advanced Condensed Matter Physics #Electronic and Structural Properties of Oxides #Magnetic and transport properties of perovskites and related materials #cond-mat.dis-nn #cond-mat.mtrl-sci
paper · pdf · doi:10.1103/physrevb.67.212301
published as Phye. Rev. B 212301 (2003) · 4 pages, 3 figures
openalex publication_date 2003/06/20 · arxiv created 2003/10/16 · arxiv updated 2009/11/30 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
The mixed-valence perovskitelike manganites are characterized by the unique interrelation of Jahn-Teller distortions, electric and magnetic properties. The Jahn-Teller distortion follows the Mn3+\ensuremath→Mn4+ charge transfer with some delay. Its development depends on the lifetime of Mn in the 3+ state, governed by the Mn4+/Mn3+ ratio and magnetic correlations. The noncoherence of Jahn-Teller distortions in orthorhombic mixed-valence manganites and rhombohedral RMnO3 (R=rare earth) results in oxygen disorder. We demonstrate that the Raman spectra in this case are dominated by disorder-induced bands, reflecting the oxygen partial phonon density of states (PDOS). The PDOS origin of the main Raman bands in insulating phases of such compounds is evidenced by the similar line shape of experimental spectra and calculated smeared PDOS and disappearance of the PDOS bands in the ordered ferromagnetic metallic phase.