Many unusual behaviors in complex oxides are deeply associated with the spontaneous emergence of microscopic phase separation. Depending on the underlying mechanism, the competing phases can form ordered or random patterns at vastly different length scales. By using a microwave impedance microscope, we observed an orientation-ordered percolating network in strained Nd 1/2Sr1/2MnO3 thin films with a large period of 100 nanometers. The filamentary metallic domains align preferentially along certain crystal axes of the substrate, suggesting the anisotropic elastic strain as the key interaction in this system. The local impedance maps provide microscopic electrical information of the hysteretic behavior in strained thin film manganites, suggesting close connection between the glassy order and the colossal magnetoresistance effects at low temperatures.
Bibliographical noteKAUST Repository Item: Exported on 2020-10-01
Acknowledged KAUST grant number(s): KUS-F1-033-02
Acknowledgements: We thank X.-L. Qi, Y. Chen, J. C. Davis, and S. A. Kivelson for valuable discussions. The work is supported by NSF (grants DMR-0906027 and Center of Probing the Nanoscale PHY-0425897), Department of Energy (DE-FG03-01ER45929-A001), Funding Program for World-Loading Innovative R and D on Science and Technology (FIRST) of Japan Society for the Promotion of Science (JSPS), and King Abdullah University of Science and Technology Fellowship (KUS-F1-033-02). Stanford University has filed a patent application with the U.S. Patent Office on the AFM compatible microwave imaging technique. This technology was modified for low-temperature measurement in this report.
This publication acknowledges KAUST support, but has no KAUST affiliated authors.