We report the unusual transport properties found in La2/3MnO3−δ
thin films on Al2O3 (102).
Powder x-ray diffraction shows that the film has a mixture of perpendicular (110) and (001) crystal orientations. Unlike epitaxial or polycrystalline La1−xMnO3−δ
samples, in which the peak resistance temperature Tp
shifts toward a higher temperature under the influence of magnetic field, the Tp
of this particular film remains almost the same even in fields up to 5 T. The film becomes insulating at a low temperature Tm( ∼ 45 K),
but the trend is reversed by the applied magnetic field. © 1998 American Institute of Physics.