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

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 degrees 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. (C) 2015 Elsevier Inc. All rights reserved.