Size-dependent exchange bias in half-doped manganite nanoparticles

Abstract

Magnetic properties of the nanosized half-doped manganite of Sm0.5Ca0.5MnO3 with different particle sizes prepared by a sol-gel method are investigated. Exchange-bias phenomena are observed in the field-cooled magnetic hysteresis loops for these nanoparticles. The values of the exchange field, coercivity, remanence asymmetry, and remanent magnetization are found to depend strongly on the particle size. Particularly, as the particle size decreases, the exchange field shows a nonmonotonic variation with a maximum at ∼120 nm. These magnetic behaviors have been explained in terms of size effects on the charge ordered and antiferromagnetic manganite nanoparticles.