Correlation of spin, size and structure in sol-gel prepared doped BiFeO3 nanoparticles

Abstract

Undoped and Gd-doped BiFeO3 nanoparticles were synthesized by sol-gel method. Particle size variation ranging from 16 to 150 nm was achieved by varying calcination temperature. The samples retained rhombohedral phase for undoped BiFeO3 nanoparticles while gets distorted on Gd-doping. The incomplete spin compensation and modification of spin cycloid structure majorly resulted in enhanced ferromagnetism in smallest Gd-doped BiFeO3 nanoparticles (16 nm). The morphological detection of small nanosized grains in the Gd-doped BiFeO3 nanoparticles were found to primarily obstruct the mobility of charge carriers yielding better insulation that led to enhanced dielectric constant and polarization values in smallest sized Gd-doped BiFeO3 nanoparticles. The magnetic and electric parameters are found to show a strong particle size dependence.