Magnetic and Magnetoabsorption Studies in Multiferroic ${\rm Ga}_{2-{\rm x}}{\rm Fe}_{\rm x}{\rm O}_{3}$ Nanoparticles

We report a comparative study of magnetic and magnetoabsorption properties of bulk and nanoparticles of Ga
_2-x
Fe
_x
O
₃
(x ≈ 1.25) compounds synthesized using sol-gel method. The average size of Ga
_2-x
Fe
_x
O
₃
nanoparticles is found to be 100 nm. We observe an enhancement in the ferrimagnetic transition temperature (T
_C
=354 K) of Ga
_2-x
Fe
_x
O
₃
nanoparticles compared to T
_C
=298 K of the bulk Ga
_2-x
Fe
_x
O
₃
. The bulk and nanoparticles of Ga
_2-x
Fe
_x
O
₃
exhibit a large coercive field (H
_C
) of H
_C
= 0.95 and 0.8 T at T= 10 K, respectively and we observe that the H
_C
decreases dramatically with increasing temperature. Magnetoabsorption was studied with a LC resonance technique and we found a close correlation between the shift in the resonance frequency due to applied magnetic field and the coercive field measured using dc magnetization measurements. We discuss the possible origins of the observed effects in both bulk and nanoparticles of Ga
_2-x
Fe
_x
O
₃
compounds.