ANISOTROPIC MAGNETORESISTANCE IN TETRAGONAL LA1-XCAXMNO-DELTA THIN-FILMS

We have fabricated thin films of La1-xCaxMnOdelta with tetragonal symm etry. For low temperatures and magnetic fields the measured magnetores istance is anisotropic: initially positive for applied magnetic field perpendicular to the film plane and negative for field applied paralle l to the film plane. At high temperatures the magnetoresistance is neg ative for all fields and field orientations. We also observe an in-pla ne magnetoresistance anisotropy with an angular dependence correspondi ng to that observed in transition metal ferromagnets. We suggest an in terpretation requiring a substantial spin-orbit interaction in the mat erial. (C) 1996 American Institute of Physics.