Materials Chemistry and Physics, Vol.120, No.1, 75-78, 2010
Facile synthesis of Ca-doped manganite nanoparticles by a nonaqueous sol-gel method and their magnetic properties
Perovskite manganite La1-xCaxMnO3 (x = 1/3,1/2 and 2/3) nanoparticles with the average particle size of about 20 nm have been synthesized by a facile nonaqueous sol-gel method using methanol as a solvent and characterized by X-ray diffraction, transmission electron microscopy and superconducting quantum interference device magnetometer. Magnetic measurements reveal that although their bulk counterparts have quite different magnetic ground states, the three-nanosized samples exhibit similar ferromagnetic behaviors below about 270 K. This result implies that with the particle size reduced to nanoscale, the ferromagnetism for x = 1/3 is weaken, while it is enhanced, accompanied by the suppression of the charge ordering, for x = 1/2 and 2/3. Moreover, the exchange bias phenomena are observed in the two latter nanoparticles, which is of special interest for potential applications. (C) 2009 Elsevier B.V. All rights reserved.