TY  - JOUR
AU  - Niermann, D.
AU  - Waschkowski, F.
AU  - de Groot, J.
AU  - Angst, M.
AU  - Hemberger, J.
TI  - Dielectric Properties of Charge-Ordered LuFe2O4 Revisited: The Apparent Influence of Contacts
JO  - Physical review letters
VL  - 109
SN  - 0031-9007
CY  - College Park, Md.
PB  - APS
M1  - PreJuSER-22298
SP  - 016405
PY  - 2012
N1  - This work has been funded by the DFG through SFB608 (Cologne). Support from the initiative and networking fund of Helmholtz Association by funding the Helmholtz University Young Investigator Group "Complex Ordering Phenomena in Multifunctional Oxides" is gratefully acknowledged. M. A. thanks D. Mandrus, B. C. Sales, W. Tian and R. Jin for their assistance during sample synthesis, supported by US DOE.
AB  - We show results of broadband dielectric measurements on the charge ordered, proposed to be multiferroic material LuFe2O4. The temperature and frequency dependence of the complex permittivity as investigated for temperatures above and below the charge-order transition near T-CO approximate to 320 K and for frequencies up to 1 GHz can be well described by a standard equivalent-circuit model considering Maxwell-Wagner-type contacts and hopping induced ac conductivity. No pronounced contribution of intrinsic dipolar polarization could be found, and thus the ferroelectric character of the charge order in LuFe2O4 has to be questioned.
KW  - J (WoSType)
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000306323900011
DO  - DOI:10.1103/PhysRevLett.109.016405
UR  - https://juser.fz-juelich.de/record/22298
ER  -