Grain size effect on magnetic and dielectric properties of hexagonal YbMnO3 nanoparticles

Abstract

We have synthesized a series of YbMnO3 nanoparticles with different grain sizes (25–450 nm) and study the effect of grain size on their structural, magnetic, and dielectric properties. The YbMnO3 nanoparticles crystallized in hexagonal perovskite-type structure. It shows that magnetic and dielectric properties are strongly dependent on the grain size. The magnetic characterization indicates that with increasing grain size, the antiferromagnetic (AFM) transition temperature increases from 70 to 86 K. A corresponding shift in the peak-positions of dielectric anomaly and AFM transition temperature is observed, indicating a strong correlation between the magnetic ordering and the electric polarization. As evidenced by the variation in the ab-plane lattice parameters and Mn-O bond lengths, the AFM interactions and dielectric anomalies of YbMnO3 can be effectively modulated by varying grain size.