TY  - JOUR
AU  - Angst, Manuel
AU  - Adiga, Shilpa
AU  - Gorfman, Semen
AU  - Ziolkowski, Michael
AU  - Strempfer, Jörg
AU  - Grams, Christoph
AU  - Pietsch, Manuel
AU  - Hemberger, Joachim
TI  - Intrinsic Ferroelectricity in Charge-Ordered Magnetite
JO  - Crystals
VL  - 9
IS  - 11
SN  - 2073-4352
CY  - Basel
PB  - MDPI
M1  - FZJ-2019-05206
SP  - 546
PY  - 2019
AB  - Single crystalline magnetite Fe 3 O 4 was investigated at low temperatures in the charge ordered state by electric measurements and time-resolved diffraction with voltage applied in-situ. Dielectric spectroscopy indicates relaxor ferroelectric characteristics, with polarization switching observably only at sufficiently low temperatures and in a suitably chosen time-window. PUND measurements with a ms time scale indicate a switchable polarization of about 0.6μC/cm2 . Significant switching occurs only above a threshold field of about 3kV/mm , and it occurs with a time delay of about 20μs . The time-resolved diffraction experiment yields, for sufficiently high voltage pulses, a systematic variation by about 0.1 % of the intensity of the ( 2,2¯,10¯¯¯¯ ) Bragg reflection, which is attributed to structural switching of domains of the non-centrosymmetric Cc structure to its inversion twins, providing proof of intrinsic ferroelectricity in charge ordered magnetite.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000502270800001
DO  - DOI:10.3390/cryst9110546
UR  - https://juser.fz-juelich.de/record/865929
ER  -