Scaling spin-phonon and spin-spin interactions in magnetoelectric Gd1-xYxMnO3



R. Vilarinho, E. C. Queirós, A. Almeida, P. B. Tavares, M. Guennou, J. Kreisel, and J. Agostinho Moreira


Journal of Solid State Chemistry, vol. 228, pp. 76-81, 2015


We present a systematic study of the structure and lattice dynamics at room temperature, and the phonon behavior at low temperatures in orthorhombic Gd1−xYxMnO3 manganites, with 0≤x≤0.4. Powder x-ray diffraction and Raman scattering at ambient conditions reveal that the Jahn–Teller distortion is composition-independent, while the Mn–O1–Mn bond angle increases by about 0.5° from x=0 to x=0.4. The spin–phonon coupling was ascertained from the relation between the renormalized wavenumber of the in-plane O2 stretching mode, associated with the spin–spin correlation function. The balance between competitive magnetic interactions is discussed based on the temperature dependence of the phonon frequency renormalization.



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