Vol.:(0123456789) 1 3
Journal of Inorganic and Organometallic Polymers and Materials
https://doi.org/10.1007/s10904-020-01459-z
Structural and Electrical Properties of Lead‑Free Perovskite:
Bi(Sr
0.25
Ti
0.25
Fe
0.5
)O
3
Varsa Purohit
1
· R. N. P. Choudhary
1
· Madhusmita Sahu
1
Received: 30 December 2019 / Accepted: 27 January 2020
© Springer Science+Business Media, LLC, part of Springer Nature 2020
Abstract
The polycrystalline bismuth strontium ferric titanate (Bi(Sr
0.25
Ti
0.25
Fe
0.5
)O
3
), synthesized via a high-temperature solid-state
reaction route, has been characterized by using different experimental procedures. Study of basic crystal structure with the
help of X-ray diffraction data of the compound exhibits the rhombohedral crystal system. The quality of the sample was
asserted by studying its microstructure and morphology. Detailed investigations of dielectric and electrical properties of
Bi(Sr
0.25
Ti
0.25
Fe
0.5
)O
3
in a broad frequency (1 kHz–1 MHz) and temperature (25–450 °C) ranges have provided various
important information on conduction mechanism, structure-properties correlationship, etc. The high dielectric constant and
relativly low tangent loss with multiple phase transitions have been observed in the material I the experimental frequency
and temperature ranges.
Keywords Lead free ceramic · Rhombohedral structure · Non Debye relaxation
1 Introduction
The design and development of electronic materials for
device applications are generally based on structural type
and their properties. The majority of the functional materi-
als developed so far for variety of applications are oxides
of different structural families, such as perovskite, tungsten
bronze, layer structure, etc. Among them, a large number
of materials belong to perovskite structural family because
of their interesting physical and chemical properties with
structural stability required for device applications. Perovs-
kite usually represents a type of crystal structure of a general
formula ABX
3
, in which A and B are cations and X is anion.
In a cubic perovskite structure, A cation sits at the corner
position, B cation sits at body centered position and anion
sit at face centered position [1, 2]. In an ideal cubic struc-
ture, the A cation has a 12-fold cubooctahedral coordination,
whereas the B cation has sixfold coordination surrounded by
an octahedrons of anions. In 1839, Gutsove rose discovered
the first perovskite CaTiO
3
in the Ural Mountains of Russia
[3]. The structure “Perovskite” has been named after Rus-
sian mineralogist Lev Perovski. Later many inorganic metal
oxides, like PbTiO
3
, BaTiO
3
, SrTiO
3
, BiFeO
3
were found
to have the perovskite structure. These oxides are used in
a variety of industrial applications due to their ferroelec-
tric, piezoelectric, dielectric, etc. Properties out of many
perovskite oxides, some compounds, like LiNbO
3
, BiFeO
3
,
PbTiO
3
show photo Voltaic (PV) effect due to their ferro-
electric polarization and other properties. As they do not
show good semiconducting properties, they are suitable for
PV applications [4, 5].
Recently, a major attention has been given towards devel-
oping dielectric ceramics having high dielectric constant and
low tangent loss for designing devices in electronic system,
which can be operated at high temperature [6, 7]. Some lead-
based ferroelectric ceramics are mainly used in piezoelectric
appliances. Lead titanate (PbTiO
3
)-based perovskite com-
pounds including Pb(ZrTi)O
3
with an morphotropic phase
boundary (MPB) build up a majority of the actual market
of piezoelectric materials [8]. But recent concerns on using
lead-free materials for devices is more noticeable because
of the toxic nature of lead based materials which should be
avoided. They can cause severe harmful and harsh effect to
the environment and human life. In view of the above, bis-
muth-constituent oxide systems are considered to be a suit-
able substitute to lead-based materials [9, 10]. On account
* Varsa Purohit
varsapurohit94@gmail.com
1
Department of Physics, Siksha ‘O’ Anusandhan (Deemed To
Be University), Khandagiri, Bhubaneswar, Odisha 751030,
India