Electrical transport and magnetoresistance properties of La0.67Ca0.33Mno3 film coated on pyrex glass substrate

The electrical transport and magnetoresistance properties of the polycrystalline La0.67Ca0.33MnO3 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 La0.67Ca0.33MnO3 film thickness is approximately 500 nm, and the average grain size of this sample varies between 40 and 50 nm. La0.67Ca0.33MnO3 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 (<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.