TEXTURE ANALYSIS IN LD-MOCVD PROCESSED THIN FILM GIANT MAGNETORESISTANT (LaM)MnO_3 MATERIALS

摘要

Thin films of La_(0.67)M_(0.33)MnO_3 (M = Sr), LSMO were deposited on three different sub-strates of LAO, Sapphire, and Y-ZrO_2 (YSZ) using metal-organic chemical vapor deposition methods. The effect of texture and orientation on the resistance (0 and 6 T) and magnetoresistance (MR) of (LSMO) thin films on various substrates has been investi-gated. X-ray pole figures were measured using Philips X'Pert X-ray diffractometer equipped with the PopLa analysis package. A direct correlation was observed between the lattice mismatch strain and the Structure of the thin film growth. LSMO/LAO seems to be the most perfect system for epitaxial growth due to the negligible lattice-mismatch ( 2 percent). The dominant orientation changes for the films deposited on LAO [100] and LAO [110] substrates while the transition temperature from ferromagnetic to paramagnetic state of the film on LAO [110] is 50K higher than that of the film on LAO [100]. The MR data and TMI temperature were measured using standard 4-point resistivity devices and SQUID.