Spin amplitude modulation driven magnetoelectric coupling in the new multiferroic FeTe2O5Br.
The magnetic and ferroelectric properties of the layered geometrically frustrated cluster compound FeTe2O5Br were investigated with single-crystal neutron diffraction and dielectric measurements. An incommensurate transverse amplitude modulated magnetic order with the wave vector q=(1/2,0.463,0) develops below T(N)=10.6(2) K. Simultaneously, a ferroelectric order due to exchange striction involving polarizable Te4+ lone-pair electrons develops perpendicular to q and to Fe3+ magnetic moments. The observed magnetoelectric coupling is proposed to originate from the temperature dependent phase difference between neighboring amplitude modulation waves.
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Jozef Stefan Institute, Jamova 39, 1000 Ljubljana, Slovenia.
Zaharko
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O
Zorko
A
A
Kutnjak
Z
Z
Jeglic
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Brown
P J
PJ
Jagodic
M
M
Jaglicić
Z
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Berger
H
H
Arcon
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D