Physical Properties of Porous Pure and Zr/Sn-Doped Nanocrystalline BaTiO3 Ceramics

Abstract

Polycrystalline BaTiO 3 and Ba(Ti 0.96 SnxZr 0.04-x )O 3 ceramics (x = 0.02-0.04) were prepared by a combination of solid-state and mechanochemical process and characterized at room temperature by X-ray diffraction for phase composition. Their crystal structures were found to be of the cubic and tetragonal symmetries, respectively. The grain size and porosity which were determined using Field Emission Scanning Electron Microscope (FESEM) and densitometer, respectively showed decrease and increase of relative density respectively, with increase in doping concentration. The variations of dielectric constant and loss with frequency and temperature show a maximum dielectric constant of 1660 at room temperature for Ba(Ti 0.96 Sn 0.03 Zr 0.01 )O 3 . The remnant polarization (P r ) and coercive field (E c ) of BT were found to be 581.73 V/cm and 0.27 μC/cm 2 . Increase in Sn content led to an increase in Pr of 0.58, 3.07, 3.73 C/cm 2 , and Ec of 1766.8, 2855.7, 2661.1 V/cm, respectively and are expected to lead to a significant reduction in the thickness of the multilayer ceramic capacitors. Impedance spectroscopy of polycrystalline Ba (Ti 0.96 Sn 0.02 Zr 0.02 )O 3 in a wide frequency and temperature range showed Nyquist plots with presence of grain and grain boundary at 400 C and a negative temperature coefficient of resistance (NTCR) for Ba(Ti 0.96 Sn 0.02 Zr 0.02 )O 3 .The dielectric relaxation showed a non-Debye character.

Improvement of ferroelectric properties via Zr doping in barium titanate nanoparticles

“…It decreases from 372.4 to 203.5 by 55% by increasing the frequency from 200 to 3000 kHz. This is interpreted as the weak response of the permanent Table 6 The Values of The dielectric constant e 0 o observed at room temperature (T room = 303 K), the Curie temperature (T C ), The Curie-Weiss temperature (T O ), the difference between T C and T o (DT = T C -T O ), the Curie constant (C), and diffuseness exponent (c) were all measured at 400 kHz dipoles by the increase of the frequency and the contribution of the charge carriers (ions) towards the dielectric constant decreasing [50]. Relaxation accompanies this decrease [51].…”

“…We can see that the Curie temperature T C shifted towards lower temperatures by increasing the zirconium concentration. The reason behind that may be due to the larger ion radius of the Zr ion compared to the Ti ion [50,54].…”

Influence of the Spark Plasma Sintering temperature on the structure and dielectric properties of BaTi(1-x)ZrxO3 ceramics

“…In this context, zirconium substituted barium titanate (BTZ) has attracted great attention in the last decade because of its wide range of applications, owing to its improved properties and potential to replace lead-based ferroelectric materials [2-3]. These properties include high dielectric permittivity, relatively low dielectric loss, large voltage tunability of the dielectric permittivity, good chemical stability, and attractive leadfree relaxor behavior [4][5][6].…”