Phonon Raman scattering in LaMn1−xCoxO3 (x=0, 0.2, 0.3, 0.4, and 1.0)

The Raman-active phonons in perovskite-like LaMn1−xCoxO3 (x=0, 0.2, 0.3, 0.4, and 1.0) are studied by measuring the Raman spectra at temperatures of 295 and 5 K. The changes in the spectra with Co doping are correlated with the decrease of the orthorhombic distortions. Surprisingly, more phonon lines are observed than are allowed for the rhombohedral LaCoO3 structure.