Novel electronic and magnetic properties of La_(0.5)Ca_(0.5)MnO_3 films deposited on (111) SrTiO_3 substrates

摘要

La_(0.5)Ca_(0.5)MnO_3 films of various thicknesses were epitaxially grown on (111) SrTiO_3 substrates by the pulsed laser deposition technique. Electronic and magnetic properties of the films deviate considerably from the bulk material; enhancement of electrical conductivity and drastically enlarged magnetic moment (relative to bulk value) are observed although the identified orientational relationship as revealed by X-ray diffraction technique indicates tensile epitaxial stain. Transport properties were found to depend strongly on film thickness. These results were discussed in terms of the orientation of the epitaxial strain with respect to the La_(0.5)Ca_(0.5)MnO_3 unit cell, distinguishing it from commonly used substrates.