Abstract
In this communication, preliminary structural and detailed electrical characteristics of the CaSnO3/CaSeO3-modified Bi0.5Na0.5TiO3 ceramics of a general chemical composition (1–2x) [Bi0.5Na0.5TiO3] + x (CaSnO3) + x (CaSeO3) with x = 0, 0.05, 0.10, 0.15, has been prepared by high-temperature solid-state reaction method with calcination and sintering temperature 925 °C and 950 °C, respectively, for 5 h. Structural and electrical characteristics of the parent compound have significantly been tailored by the addition of the equal percentage of CaSnO3, CaSeO3 over a wide range of temperature (25–400 °C) as well as frequency (1 kHz–1 MHz). Room-temperature X-ray diffraction (XRD) analysis confirms the development of single-phase compound (with rhombohedral symmetry) with very small amount of impurity phase in higher concentrations (x). In the dielectric spectroscopy, two dielectric peaks are observed at around the temperatures 210 °C and 320 °C indicating multiple phase transitions of different types including the ferroelectric to paraelectric through anti-ferroelectric. Impedance analysis of data exhibits both negative/and positive temperature coefficient of resistance of the materials. The Nyquist plots determine the grain and grain boundary effect in capacitive and resistive properties of the materials, and also the non-Debye type of relaxation. The room-temperature hysteresis loop confirms the existence of ferroelectricity in the compounds where as the leakage current characteristics determine the Ohmic behavior of the materials.
Highlights
In the last few decades, some lead-based ceramics with perovskite (ABO3) type of structure including Pb(Zr, Ti)O3 (PZT) have been fabricated and studied for industrial applications, such as ultrasonic transducers, sensors, actuators, microelectronic devices as well as energy harvesters because of their outstanding electrical properties [1,2,3]
Perovskite type of alkaline earth stannates having a standard formula of MSnO3 have attracted significant attention because of their extensive applications in several fields, like ferromagnets, photocatalysts, gas sensors, humidity sensor, thermally stable capacitors, ceramic dielectric bodies, anode materials used in lithium-ion batteries, and display phosphor matrix, over the previous few years
Preliminary structure study is performed by room temperature X-ray diffraction (XRD) pattern indicating the samples exhibit rhombohedral phase with the non-Centro symmetry space group R3c, achieved from JCPDS diffraction pattern
Summary
In the last few decades, some lead-based ceramics with perovskite (ABO3) type of structure including Pb(Zr, Ti)O3 (PZT) have been fabricated and studied for industrial applications, such as ultrasonic transducers, sensors, actuators, microelectronic devices as well as energy harvesters because of their outstanding electrical properties [1,2,3]. Among all rare earth stannates, CaSnO3 (i.e., CSn) represents two crystalline systems: firstly an ordered system with hexagonal along with rhombohedral symmetry (having unit-cell parameters (a = 5.487A°, c =15.287A°) as well as (a = 6.000A°, α = 54.42◦) respectively); and secondly a perovskite structure with orthorhombic phase (having space group Pbnm, with lattice parameters a = 5.5142A°, b = 5.6634A°, c =7.88162A°) This is known as a wide band gap semiconductor having a band gap of around 4.4 eV [31]. Selenites have been studied extensively because of their interesting ferroelectric properties Due to this reason, we added calcium selenites (CaSeO3) and calcium stannate (CaSnO3) in equal ratios to the parent BNT compound [33]. 2. Compound Synthesis and characterization The polycrystalline materials of CaSnO3-CaSeO3 modified (Bi0.5Na0.5)TiO3 with a general chemical formula (1–2x) [(Bi0.5Na0.5) TiO3] + x (CaSnO3) + x (CaSeO3) i.e., (BNT-CSn-CSe) with different concentrations (x=0, 0.05, 0.1, 0.15) were fabricated through cost effective solid state reaction method.
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: Journal of Materials Science: Materials in Electronics
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
