Abstract:
A simple route to prepare Gd0.7Sro.3MnO3 nanoparticles by ultrasonication of their
bulk powder materials was presented. The Gd0.7Sro.3MnO3 nanoparticles were also
prepared by high energy ball milling technique. The transmission electron
microscopic imaging demonstrated the formation of nanoparticles with average size
varied from 20-40 nm and 100-150 nm, respectively by using ultrasonication and ball
milling techniques. The bulk materials as well as nanoparticles synthesized by
ultrasonication technique exhibited a paramagnetic to spin-glass transition at 35-40 K.
On the contrary, nanoparticles synthesized by ball milling technique did not show any
phase transition, however, an upturn of magnetization was observed at low
temperature. A drastic change in the magnetic properties of ball milled
Gd0.7Sro.3MnO3 nanoparticles than that of ultrasonically prepared nanoparticles and
their corresponding bulk materials was observed. The degradation of the magnetic
properties in ball milled nanoparticles may be associated with the contamination,
amorphorization and formation of a nonmagnetic layer around the surface of the these
nanoparticles. The outcome of this investigation demonstrated the potentially of
ultrasonication technique as a physical route to prepare rare-earth based manganite
nanoparticles.
