TY  - JOUR
A1  - Elsässer, S.
A1  - Schiebl, M.
A1  - Mukhin, A. A.
A1  - Balbashov, A. M.
A1  - Pimenov, A.
A1  - Geurts, J.
T1  - Impact of temperature-dependent local and global spin order in \(R\)MnO\(_3\) compounds for spin-phonon coupling and electromagnon activity
JF  - New Journal of Physics
N2  - 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 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.
KW  - physics
KW  - RMnO3
KW  - multiferroics
KW  - electromagnon
KW  - Raman spectroscopy
KW  - spin-phonon coupling
Y1  - 2017
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-171978
VL  - 19
ER  -