Mesoscopic percolating resistance network in a strained manganite thin film.
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(1/2)Sr(1/2)MnO3 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.
Lai
Keji
K
Geballe Laboratory for Advanced Materials, Department of Physics, Stanford University, CA 94305, USA.
Nakamura
Masao
M
Kundhikanjana
Worasom
W
Kawasaki
Masashi
M
Tokura
Yoshinori
Y
Kelly
Michael A
MA
Shen
Zhi-Xun
ZX