Effects of Rare-Earth Dopants on the Ferroelectric and Pyroelectric Properties of Strontium Barium Niobate CeramicsCT: Effects of Rare-Earth Dopants on the Ferroelectric and Pyroelectric Properties of Strontium Barium Niobate Ceramics

Volume 6 Issue 6, Pages 671 – 678

Yingbang Yao, Chee Leung Mak, Kin Hung Wong, Shengguo Lu, Zhengkui Xu
Published
Online: Nov 5 2008 3:07PM

DOI: 10.1111/j.1744-7402.2008.02308.x

ABSTRACT
Effects of various rare-earth (RE) dopants (Y³⁺,
La³⁺, Ce³⁺, Pr³⁺,
Nd³⁺, Sm³⁺, Eu³⁺,
Gd³⁺, Tm³⁺, Dy³⁺,
Er³⁺, and Yb³⁺) on the
dielectric, ferroelectric, and pyroelectric properties of Sr_0.5Ba_0.5Nb₂O₆
(SBN50) ceramics were investigated. In the present studies, the doping
concentrations of all the RE dopants were fixed at 1 mol%. Their
potential usefulness in pyroelectric applications was discussed based on
their measured pyroelectric detectivity figure of merit (FOM). On the
basis of our studies, for RE dopants with atomic numbers smaller than
Nd, their dielectric constants were greatly increased, while for RE
dopants with atomic numbers larger than Sm, their dielectric constants
as well as dielectric losses became smaller. Among various dopants,
Eu-doped SBN showed the most improved ferroelectric properties. Its
remnant polarization (P_r)
was increased to 4.86 μC/cm² as compared with
3.23 μC/cm² obtained in undoped SBN50. On the
other hand, Gd-doped SBN exhibited the largest pyroelectric coefficient
of 168 μC/m² K, which was over three times of
that of the undoped sample (49 μC/m² K). The
work shows that Gd-doped SBN exhibits the greatest potential for
pyro-applications because it bears the largest FOM of 0.45 × 10⁻⁵ Pa^−0.5
[Correction: After online publication on 11/05/2008, an error was found
in this article. The original value, 1.35×10⁻⁵ Pa^−0.5,
was incorrect. The data has been replaced with the correct value.].

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