Dielectric, electric modulus, ferroelectric and magnetic properties of Bi1−xGdxFeO3 ceramics

Bi
_(1-x
)Gd
_x
FeO
₃
(BGFO, x=0.05-0.3) crystallites were synthesized by the microwave hydrothermal method. Then, the powders were sintered into shaped BGFO ceramics. The results showed that Gd
³⁺
could dramatically affect the structural, ferroelectric and magnetic behavior of BiFeO
₃
ceramics. X-ray diffraction results indicated that pure BGFO ceramics could be obtained. The morphologies of the BGFO are investigated by scanning electron microscopy. All the samples are well compact without pores and the grain are agglomerated. The dielectric constant increases and dielectric loss decreases with increasing Gd
³⁺
contents. The value of Ac-conductivity of Bi
_0.95
Gd
_0.05
FeO
₃
at 1000 kHz is in the order of ~10
^-4
, which is several orders of magnitude larger than that of Bi
_0.7
Gd
_0.3
FeO
₃
. The double peaks appearing in the plots of M' and M" with frequency for x=0.30 confirms the coexistence of grainand grain boundary effects. The introduction of Gd into BiFeO
₃
ceramics was found to improve the saturated magnetization value dramatically.