| Structural, Ferroelectric, Dielectric and Piezoelectric
Studies of Yttrium Substituted SrBi2Nb2O9 Lead-free
Relaxor Ceramics |
Jaladi Nitchal Kiran,a, * Konapala Sambasiva Rao,b Haileeyesus Workineh,c Potlakayala Prameelad and Kotikala Sowribabua
Pages : 202-211
DOI : 10.1080/0371750X.2020.1801514 |
| Abstract |
| Ferroelectric ceramic compositions SrBi2–xYxNb2O9 (x = 0.0, 0.2, 0.4, 0.6 and 0.8)
were prepared via conventional solid-state route with high density (92-99%)
establishing the sintering conditions. X-ray diffraction studies confirmed
the orthorhombic structure. The micrographs obtained from scanning
electron microscopy showed the presence of well packed and randomly
oriented needle-shaped grains with an average grain size of 1.624 m. FTIR
and Raman studies on these samples indicated the growth of single phase
perovskite material. From the dielectric studies, the phase transition
temperature (Tc) of strontium bismuth niobate (SBN) was found to be 430oC,
whereas the Tc of yttrium substituted SBN (SBYN) was found to decrease
from 400o to 370oC. The transition was diffuse and frequency dependent
which is a characteristic behavior of relaxor material. The diffuseness
parameter () was computed for all the compositions. P-E loop measurements
showed a decrease in the parameters Ps, Pr and Ec in yttrium substituted SBN
compared to SBN. Piezoelectric studies in SBN and SBYN estimated kp, d33, g33
and Qm values. Cole-Cole plots were obtained from studies on SBN and SBYN
at different temperatures in the frequency range 50 Hz to 1 MHz. The activation
energy values were computed.
[Keywords: P-E loops, Dielectric studies, Piezoelectric studies, Impedance
studies, Diffuseness parameter, Relaxor material] |
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