Temperature-dependent Raman spectra of polycrystalline La 1Ϫx Mn 1Ϫx O 3 samples, referred to as LaMnO 3ϩ␦ for convenience, were correlated to their structural and magnetic properties for different ␦. For ␦р0.05, a softening of the ϳ610 cm Ϫ1 Raman mode is observed below the magnetic ordering temperature. This softening is reduced as ␦ increases from 0.00 to 0.05. This behavior is not associated with lattice anomalies, and is interpreted in terms of a spin-phonon coupling caused by a phonon modulation of the superexchange integral. A quantitative analysis of this effect is presented. ͓S0163-1829͑99͒10737-9͔

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