Electroresistance of La-Ca-MnO Thin Films

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.

DOI: 10.12693/APhysPolA.105.107 PACS numbers: 73.50.Gr, 73.50.Lw, 73.63.Bd