ELECTRICAL TRANSPORT AND MAGNETORESISTANCE PROPERTIES OF <font>La</font>_0.67<font>Ca</font>_0.33<font>MnO</font>₃ FILM COATED ON PYREX GLASS SUBSTRATE

Abstract

The electrical transport and magnetoresistance properties of the polycrystalline La 0.67 Ca 0.33 MnO 3 film produced on a Pyrex substrate were investigated for the first time. X-ray powder diffraction indicated that the film sample has a perovskite structure. Scanning electron microscope indicated that La 0.67 Ca 0.33 MnO 3 film thickness is approximately 500 nm, and the average grain size of this sample varies between 40 and 50 nm. La 0.67 Ca 0.33 MnO 3 film showed a phase transition from paramagnetic to ferromagnetic at (T C ) 80 K and a metal–insulator transition at (T MI ) 77.5 K and at 2 mT magnetic field. The upturn of the resistance observed at low temperatures (&lt;36 K) was attributed to the Coulomb blockade, and the strong structural disorder is due to the large lattice mismatch and strain relaxation. A large magnetoresistance ratio [MR (%)] of 780% was observed at 100 K and 6 T magnetic field.