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Electroresistance of La--Ca--MnO Thin Films |
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P. Cimmperman
a
, V. Stankevic
a
, N. Zurauskiene
a
, S. Balevicius
a
, F. Anisimovas
a
, J. Parseliunas
a
, O. Kiprijanovic
a
and L.L. Altgilbers
b
a Semiconductor Physics Institute, A. Gostauto 11, Vilnius, Lithuania b US Army Space and Missile Defense Command, Huntsville AL, USA |
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| Epitaxial, textured, and polycrystalline La 0.7 Ca 0.3 MnO 3 films, having about 150 nm thickness, were prepared by pulsed laser deposition techniques onto (110) NdGaO 3 , MgO and lucalox substrates and investigated using 10ns duration, 0.5ns rise time electrical pulses having amplitude up to 500V. Electroresistance of the films [R(E)-R(0)]/R(0) was investigated up to 80kV/cm electric field strengths in temperatures ranging from 300K to 4.2K. Strong (up to 93%) negative electroresistance was obtained in polycrystalline La 0.7 Ca 0.3 MnO 3 films prepared on MgO and lucalox substrates. The epitaxial films grown on NdGaO 3 substrate demonstrated only a small resistance change due to Joule heating induced by a current pulse. It was concluded that electroresistance manifests itself in strongly inhomogeneous manganites films exhibiting a large number of structural imperfections producing ferromagnetic tunnel junction nets. |
| PACS numbers: 73.50.Gr, 73.50.Lw, 73.63.Bd |