Influence of the morphology on the magneto-transport properties of laser-ablated ultrathin La0.7Ba0.3MnO3 films
Das, A. ; Gordon, I. ; Wagner, P. ; Cannaerts, M. ; Moshchalkov, V. V. ; Bruynseraede, Y.
[S.l.] : American Institute of Physics (AIP)
Published 2001
[S.l.] : American Institute of Physics (AIP)
Published 2001
| ISSN: |
1089-7550
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|---|---|
| Source: |
AIP Digital Archive
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| Topics: |
Physics
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| Notes: |
We investigate the thickness dependent properties of manganite films characterized by colossal negative magnetoresistance. Ultrathin, wedge-type films (0–120 Å) of La0.7Ba0.3MnO3 were deposited by laser ablation onto SrTiO3 and LaAlO3 substrates. The films were patterned into strips of different thickness and magneto-transport measurements were performed at temperatures between 5 and 290 K and in magnetic fields up to 5 T. Atomic force- and transmission electron microscopy were done to correlate the microstructure with the transport data. The resistivity of the films increases slightly with decreasing thickness due to substrate-induced compressive strain. Below 50 Å, the resistivity rises abruptly indicating a crossover to discontinuous and finally island-like film growth as confirmed by the microstructural techniques. At thicknesses slightly above the threshold for percolative conduction ((approximate)30 Å), an enhanced low-field magnetoresistance was observed as a signature of spin-dependent tunneling. © 2001 American Institute of Physics.
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| Type of Medium: |
Electronic Resource
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| URL: |