TY  - JOUR
AU  - Lee, J.H.
AU  - Fang, L.
AU  - Vlahos, E.
AU  - Ke, X.
AU  - Jung, Y.W.
AU  - Fitting Kourkoutis, L.
AU  - Kim, J.W.
AU  - Ryan, P.
AU  - Heeg, T.
AU  - Roeckerath, M.
AU  - Goian, V.
AU  - Bernhagen, M.
AU  - Uecker, R.
AU  - Hammel, C.
AU  - Rabe, K.M.
AU  - Kamba, S.
AU  - Schubert, J.
AU  - Freeland, J.W.
AU  - Muller, D.A.
AU  - Fennie, C.J.
AU  - Schiffer, P.
AU  - Gopalan, V.
AU  - Johnston-Halperin, E.
AU  - Schlom, D.G.
TI  - A strong ferroelectric ferromagnet created by means of spin-lattice coupling
JO  - Nature 
VL  - 466
SN  - 0028-0836
CY  - London [u.a.]
PB  - Nature Publising Group
M1  - PreJuSER-11208
SP  - 954 - 958
PY  - 2010
N1  - The authors acknowledge discussions and interactions with M. D. Biegalski, D. H. A. Blank, C. B. Eom, M. B. Holcomb, M. Lezaic, J. Mannhart, L. W. Martin, D. V. Pelekhov, R. Ramesh, K. Z. Rushchanskii, N. Samarth, A. Schmehl, D. A. Tenne, J.-M. Triscone, D. Viehland and L. Yan. In addition, the financial support of the National Science Foundation through grant DMR-0507146 and the MRSEC program (DMR-0520404, DMR-0820404 and DMR-0820414), and of the Czech Science Foundation (project no. 202/09/0682), is gratefully acknowledged. Use of the Advanced Photon Source was supported by the US Department of Energy, Office of Science, Office of Basic Energy Sciences, under contract no. DE-AC02-06CH11357.
AB  - Ferroelectric ferromagnets are exceedingly rare, fundamentally interesting multiferroic materials that could give rise to new technologies in which the low power and high speed of field-effect electronics are combined with the permanence and routability of voltage-controlled ferromagnetism. Furthermore, the properties of the few compounds that simultaneously exhibit these phenomena are insignificant in comparison with those of useful ferroelectrics or ferromagnets: their spontaneous polarizations or magnetizations are smaller by a factor of 1,000 or more. The same holds for magnetic- or electric-field-induced multiferroics. Owing to the weak properties of single-phase multiferroics, composite and multilayer approaches involving strain-coupled piezoelectric and magnetostrictive components are the closest to application today. Recently, however, a new route to ferroelectric ferromagnets was proposed by which magnetically ordered insulators that are neither ferroelectric nor ferromagnetic are transformed into ferroelectric ferromagnets using a single control parameter, strain. The system targeted, EuTiO(3), was predicted to exhibit strong ferromagnetism (spontaneous magnetization, approximately 7 Bohr magnetons per Eu) and strong ferroelectricity (spontaneous polarization, approximately 10 microC cm(-2)) simultaneously under large biaxial compressive strain. These values are orders of magnitude higher than those of any known ferroelectric ferromagnet and rival the best materials that are solely ferroelectric or ferromagnetic. Hindered by the absence of an appropriate substrate to provide the desired compression we turned to tensile strain. Here we show both experimentally and theoretically the emergence of a multiferroic state under biaxial tension with the unexpected benefit that even lower strains are required, thereby allowing thicker high-quality crystalline films. This realization of a strong ferromagnetic ferroelectric points the way to high-temperature manifestations of this spin-lattice coupling mechanism. Our work demonstrates that a single experimental parameter, strain, simultaneously controls multiple order parameters and is a viable alternative tuning parameter to composition for creating multiferroics.
KW  - Electric Capacitance
KW  - Electricity
KW  - Europium: chemistry
KW  - Magnetics
KW  - Microscopy, Electron, Scanning Transmission
KW  - Oxides: chemistry
KW  - Temperature
KW  - Titanium: chemistry
KW  - X-Ray Diffraction
KW  - Oxides (NLM Chemicals)
KW  - europium titanium trioxide (NLM Chemicals)
KW  - Titanium (NLM Chemicals)
KW  - Europium (NLM Chemicals)
KW  - J (WoSType)
LB  - PUB:(DE-HGF)16
C6  - pmid:20725036
UR  - <Go to ISI:>//WOS:000281030300030
DO  - DOI:10.1038/nature09331
UR  - https://juser.fz-juelich.de/record/11208
ER  -