Brillouin light scattering in CMR manganite films

• Published in: Physica. B, Condensed matter Vol. 320; no. 1; pp. 119 - 121
• Main Authors: Machado, F.L.A, Lucena, M.A, de Araújo, A.E.P, Azevedo, A, de Aguiar, F.M, Rezende, S.M, Nigam, A.K
• Format: Journal Article Conference Proceeding
• Language: English
• Published: Amsterdam Elsevier B.V 01.07.2002; Elsevier
• Subjects: Brillouin light scattering; Colossal magnetoresistance; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Condensed matter: structure, mechanical and thermal properties; Exact sciences and technology; Lattice dynamics; Magnetic properties and materials; Magnetotransport phenomena, materials for magnetotransport; Manganites; Phonons and vibrations in crystal lattices; Phonons in crystal lattices; Physics; Brillouin light scattering; Lattice dynamics; Manganites; Inorganic compounds; Phonon-phonon interactions; Light scattering; Transition element compounds; Doping; Colossal magnetoresistance; Rare earth compounds; Spectral line shift; Thin films; Frequency shift; Strontium Manganites; Anisotropy; Brillouin effect; Calcium Manganites; Phonon mode; Phonon scattering; Quaternary compounds; Ionic bonds; Phonon spectra; Lanthanum Manganites
• ISSN: 0921-4526; 1873-2135
• DOI: 10.1016/S0921-4526(02)00658-0

Thin films of La 0.7A 0.3MnO 3 (A=Ce, Ca, and Sr) and La 0.55Ho 0.15Sr 0.3MnO 3 manganites have been investigated by Brillouin light scattering at room temperature. The phonon spectra for the Ce-doped sample showed an interesting three-peak structure at frequency shifts of 11.4, 13.8 and 16.1 GHz, with negligible dispersion and in-plane anisotropy. For a fixed scattering angle, the phonon spectrum of the other samples showed a broad peak at a smaller frequency (<10 GHz). It is shown that the observed phonon frequency decreases with increasing ionic character of the La–Mn bonds resulting from the replacement of part of the atoms of La by Ce, Ca, Sr and Ho.