The Raman spectra of epitaxial thin films of La 2 CoMnO 6 on ͑001͒-oriented SrTiO 3 substrates have been measured in several exact scattering configuration between 12 and 890 K. The polarization dependence of the spectra provide clear evidence for ordered P12 1 / n1 structure, differing from its parent Fm3m structure by the presence of rotational distortions. The correlation between the phonon modes in Fm3m, R3, and P12 1 / n1 phases is analyzed and the corresponding types of atomic motions as

more »

... ell as their expected frequency range are determined by comparison to the predictions of lattice dynamical calculations. The ferromagnetic ordering and spin-phonon coupling below T C result in softening of some of the phonon modes. The evolution of the Raman spectra at high temperatures shows no indication for P12 1 / n1-R3 transition up to 800 K.