The Microstructural, Dielectric, Pyroelectric and Ferroelectric Properties of SrBi₂(Nb_1-xV_x)₂O₉(0 ≤ x ≤ 0.3) Ceramics

Layered SrBi₂(Nb_1−x V _x )₂O₉ (SBVN) ceramics with x ranging from 0 to 0.3 (30 mol%) were fabricated via the conventional sintering technique. A remarkable transformation in the microstructure of SBN ceramic was encountered as the V₂O₅ content increased from 3–30 mol%. The average grain size of the SBN ceramic containing V₂O₅ was found to increase with increase in V₂O₅ content. The dielectric constant (ϵ _r ) as well as the dielectric loss (D) increased with increase in grain size (6 μm–17 μm). The ferroelectric to paraelectric transition temperature (T _c ) shifted to higher temperature with increasing grain size. The pyroelectric coefficient was positive at 300 K and increased with increasing grain size. Interestingly, the SrBi₂(Nb_0.7V_0.3)₂O₉ (x = 0.3) ceramics with a grain size of 17 μm exhibited higher remnant polarization (P _r ) and lower coercive field (E _c ) than those with grains of 7 μm. The Curie-Weiss constant that was obtained for these ceramics was in line with that of displacive type ferroelectrics.

Keywords:

• Strontium bismuth niobate
• grain size effect
• dielectric properties
• pyroelectric properties
• ferroelectric properties

PACS:

• 77.22.-d
• 77.80.Bh
• 77.84.-s

Acknowledgments

The authors thank the Department of Science and Technology, Government of India for financial grant. They also thank Mr. Vynatheya for his help in carrying out scanning electron microscopy.