## Impact of temperature-dependent local and global spin order in $$R$$MnO$$_3$$ compounds for spin-phonon coupling and electromagnon activity

Please always quote using this URN: urn:nbn:de:bvb:20-opus-171978
• The orthorhombic rare-earth manganite compounds $$R$$MnO$$_3$$ show a global magnetic order for $$T$$ < $$T$$$$_N$$, and several representatives are multiferroic with a cycloidal spin ground state order for $$T$$ < $$T$$$$_c$$$$_y$$$$_c$$$$_l$$ < $$T$$$$_N$$ $$\approx$$ 40 K. We deduce from the temperature dependence of spin–phonon coupling in Raman spectroscopy for a series of $$R$$MnO$$_3$$ compounds that their spin order locally persists up to about twice $$T$$$$_N$$. Along the same line, our observation of the persistence of theThe orthorhombic rare-earth manganite compounds $$R$$MnO$$_3$$ show a global magnetic order for $$T$$ < $$T$$$$_N$$, and several representatives are multiferroic with a cycloidal spin ground state order for $$T$$ < $$T$$$$_c$$$$_y$$$$_c$$$$_l$$ < $$T$$$$_N$$ $$\approx$$ 40 K. We deduce from the temperature dependence of spin–phonon coupling in Raman spectroscopy for a series of $$R$$MnO$$_3$$ compounds that their spin order locally persists up to about twice $$T$$$$_N$$. Along the same line, our observation of the persistence of the electromagnon in GdMnO$$_3$$ up to $$T$$ $$\approx$$ 100 K is attributed to a local cycloidal spin order for $$T$$ > $$T$$$$_c$$$$_y$$$$_c$$$$_l$$, in contrast to the hitherto assumed incommensurate sinusoidal phase in the intermediate temperature range. The development of the magnetization pattern can be described in terms of an order–disorder transition at $$T$$$$_c$$$$_y$$$$_c$$$$_l$$ within a pseudospin model of localized spin cycloids with opposite chirality.