Annealing effect on the characteristics of La 0.67Sr 0.33MnO 3 polycrystalline thin films produced by the sol-gel dip-coating process


Goktas A., Aslan F., Mutlu İ. H.

Journal of Materials Science: Materials in Electronics, vol.23, no.2, pp.605-611, 2012 (SCI-Expanded) identifier

Abstract

The effect of annealing temperature on selected characteristics of polycrystalline La 0.67Sr 0.33MnO 3 films, which have been produced on quartz substrates, was investigated. X-Ray powder diffraction patterns showed that the phase formation started at 873 K and all the films had perovskite structure. By increasing the annealing temperature, the lattice parameters were decreased. Scanning electron microscope indicated that the film thicknesses were approximately 3 μm and the average grain size of the samples varied between 30-100, 50-110, 70-120, and 100-150 nm for films annealed at 873, 973, 1,073, and 1,173 K, respectively. All the films showed a paramagnetic-ferromagnetic (T C) and metal-insulator (T IM) phase transition. The T C indicated a small variation [from 131 K (S4) to 124 K (S1)] as a function of annealing temperature, whereas the T IM went down from 212 K (S4) to 110 K (S1), a strong decrease of 102 K. A colossal magneto resistance with magneto resistance ratios of 130, 139, 156, and 163% were observed near T C and at 6 T magnetic field. © 2011 Springer Science+Business Media, LLC.