Characteristics of nano-sized La0.7Ca0.3MnO3 powders prepared by solution combustion method and solid state reaction method for CMR applications

La0.7Ca0.3MnO3 powders were prepared by both solution combustion method (SCM) and solid state reaction method (SSRM) and they were calcined at various calcination temperatures and time intervals in the air. In the SSRM, single phase La0.7Ca0.3MnO3 was obtained after heat-treatment of the powder at 1000 °C for 24 h. However, in the SCM, single phase nano-sized La0.7Ca0.3MnO3 powder could be obtained easily when the powder was heat-treated at 650 °C for 1 h only. Specific surface area of the polycrystalline La0.7Ca0.3MnO3 powder, using this method (SCM), was measured to be 92 m2/g. The specific surface area was about 26-fold larger than that of the SSRM powder.