Size dependent modifications in the physical properties of chemical solution deposition and pulsed laser deposition grown La_0.7Ca_0.3MnO₃ manganite thin films: A comparative study

摘要

Grain-size dependence of electronic transport and magnetoresistance (MR) properties of nanostructured La_0.7Ca_0.3MnO₃ (LCMO) manganite thin films grown using pulsed laser deposition (PLD) and chemical solution deposition (CSD) have been compared in the context of the grain size, surface and strain modification due to the different synthesis techniques used as well as due to substrate induced magnetic anisotropy. CSD grown LCMO thin films shows the grain size ~70 nm while grain size ~150 nm is exhibited by PLD grown films resulting in an appreciable change in the strain and low temperature magnetoresistance (LTMR). In CSD grown film, nanostructured grains exhibit sharp magnetic orientation in the absence of strain resulting in the observation of large maximum TCR value ~10.1% K^-1 at 235 K as compared to PLD grown film (TCR value ~2.7% K^-1 at 194 K). Epitaxial thin films grown by the CSD technique are strain free and possess nanostructured grains size resulting into better physical properties as compared to PLD grown LCMO films.