Doping fluctuation-driven magneto-electronic phase separation in La1-xSrxCoO3 single crystalsC. He1, S. El-Khatib1, 2, J. Wu1, J. W. Lynn2, H. Zheng3, J. F. Mitchell3 and C. Leighton1
1 Department of Chemical Engineering and Materials Science, University of Minnesota Minneapolis, MN 55455, USA
2 NIST Center for Neutron Research, National Institute for Standards and Technology Gaithersburg, MD 20899, USA
3 Materials Science Division, Argonne National Laboratory - Argonne, IL 60439, USA
received 5 June 2009; accepted in final form 9 July 2009; published July 2009
published online 5 August 2009
In recent years it has become clear that complex oxides provide an exceptional platform for the discovery of new physics as well as a considerable challenge to our understanding of correlated electrons. The tendency of these materials to display nanoscale electronic and magnetic inhomogeneity is a good example. Here, we have applied a variety of experimental techniques to investigate this magneto-electronic phase separation in a model system —the doped cobaltite La1-xSrxCoO3. Comparing experimental data over a wide range of doping with statistical simulations, we conclude that the magneto-electronic inhomogeneity is driven solely by inevitable local compositional fluctuations at nanoscopic length scales. The phase separation is thus doping fluctuation-driven rather than electronically driven, meaning that more complex electronic phase separation models are not required to understand the observed phenomena in this material.
75.30.Kz - Magnetic phase boundaries (including magnetic transitions, metamagnetism, etc.).
71.30.+h - Metal-insulator transitions and other electronic transitions.
72.15.Gd - Galvanomagnetic and other magnetotransport effects.
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