Microstructure, magnetoresistance and electrical properties of La0.67Sr0.33MnO3 films synthesized from citric acid and ethylene glycol

The polycrystal La0.67Sr0.33MnO3 (LSMO) thin films were grown on Si (100) substrates by utilizing the resins synthesized from the polymerization of citric acid and ethylene glycol. The microstructure, magnetoresistance and electrical resistivity of films obtained from various gelation times and annealing temperatures were investigated. The results show that when the resin was gelled at 100 h, a pseudocubic perovskite can be synthesized, which exhibited a higher magnetoresistivity (MR%) of 6.57%. The temperature of maximum resistivity (Tp) was close to room temperature with the rise in annealing temperature. In particular, the sample was produced from the resin, obtained by molar ratio of citric acid to metal ions at 4, gelled for 100 h and annealed at 800 °C for 4 h, the Tp occurred at 296 K and the low-temperature MR% of the film at 70 K was 20.38%.