Abstract:
Piezoelectricity has an important role in our daily life especially in electronic indus
tries. Dielectric, ferroelectric, and piezoelectric properties including phase transition
temperatures of perovskite-type bismuth sodium titanate, (B'i
o
.
5
Nao.5)Ti0
[BNT]
based lead-free piezoelectric ceramics have been studied from
the the view point of
being candidates for lead-free piezoelectric materials
to reduce environmental damage.
The phenomenological theory of phase transition is presented using Landau-Ginzburg
Devonshire formalism.
The spontaneous polarization as a function of temperature for
both first and second order phase transitions and the temperature dependence of the
dielectric constant of BNT are discussed.
Key words : Dielectric, Landau equation, lead free piezoelectric, phase transition,
BNT.
