Microwave dielectric properties have been investigated on the solid solution series (BaxSr1-x)(Zn1/3Ta2/3)O3 with x = 0, 0.3, 0.5, 0.7, 1.0. The variation in dielectric constant (ε) and temperature coefficient of resonant frequency (τf) with respect to x are not monotonous. An anomaly exists for the composition Ba0.5Sr0.5(Zn1/3Ta2/3)O3. The Q × f product decreases with increase in the Sr concentration. The dielectric properties of these compounds are related to the structural distortion due to octahedra tilting.

Vemuri Rama Krishna Murthy

BARIUM COMPOUNDS

Composition

Crystal defects

Dielectric devices

Dielectric properties

Microwave Measurement

Permittivity measurement

Perovskite

Solid solutions

Temperature

OCTAHEDRAL TILTING

STRUCTURAL DISTORTION

TOLERANCE FACTOR

Resonators

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IIT Madras

Microwave dielectric properties of (Ba, Sr)(Zn1/3Ta2/3)O3 dielectric resonators

Materials Chemistry and Physics

The aim of this work is to understand the effect of the tilting of octahedra on polar phonon modes of lattice vibration, which contributes a major part to the dielectric polarization in the crystal. The tolerance factor, which is a measure of the packing of ions in the perovskite unit cell, determines the tilting of oxygen octahedra in the perovskite materials. In this work we have discussed the variation of polar phonon frequencies with respect to the tolerance factor in the composition (Ba(1-x)Srx)(Zn1/3Ta2/3)O3 with x = 0.0, 0.3, 0.5, 0.7, 1.0. The dielectric properties measured at the microwave frequency range are also highlighted to support the ideas proposed in this paper.

Physica B: Condensed Matter

Far-IR reflectance study on (Ba(1-x)Srx)(Zn1/3Ta2/3)O3 dielectric resonators as a function of tolerance factor

(Ni1-xZnx)Nb2O6, 0≤x≤1.0, ceramics with &gt;97% density were prepared by a conventional solid-state reaction, followed by sintering at 1200°-1300°C (depending on the value of x). The XRD patterns of the sintered samples (0≤x≤1.0) revealed single-phase formation with a columbite (Pbcn) structure. The unit cell volume slightly increased with increasing Zn content (x). All the compositions showed high electrical resistivity (ρdc=1.6±0.3 × 10 11 Ω·cm). The microwave (4-5 GHz) dielectric properties of (Ni1-xZnx)Nb2O6 ceramics exhibited a significant dependence on the Zn content and to some extent on the morphology of the grains. As x was increased from 0 to 1, the average grain size monotonically increased from 7.6 to 21.2 μm and the microwave dielectric constant (ε′r) increased from 23.6 to 26.1, while the quality factors (Qu × f) increased from 18 900 to 103 730 GHz and the temperature coefficient of resonant frequency (τf) increased from -62 to -73 ppm/°C. In the present work, we report the highest observed values of Qu × f=103 730 GHz, and ε′r=26.1 for the ZnNb2O6-sintered ceramics. © 2009 The American Ceramic Society.

Journal of the American Ceramic Society

High Q microwave dielectric ceramics in (Ni1-x Zn x)Nb2O6 system

The microwave characteristics of (Ca0.6,Sr0.4)ZrO3 were studied with Substitution of Ti in the place of Zr. The Substitution of Ti for Zr affects the microwave dielectric properties of (Ca0.6,Sr0.4)ZrO3, in that both the dielectric constant (εr) and temperature coefficient of resonant frequency (τf) increase and Q factor decreases. The results are discussed in terms of change of octahedral tilting with composition and temperature. © 1995, Taylor &amp; Francis Group, LLC. All rights reserved.

Ferroelectrics

Influence of structure on the microwave dielectric properties of ti substituted (Ca, Sr)ZrO3 ceramics

Microwave Characteristics of (Zr, Sn)TiO4 and BaO-PbO-Nd2O3-TiO2 Dielectric Resonators

Journal of Applied Physics

B‐site order and infrared reflectivity inA(B’B‘)O3complex perovskite ceramics

Japanese Journal of Applied Physics

Dielectric and Structural Characteristics of Ba- and Sr-based Complex Perovskites as a Function of Tolerance Factor

Anomaly of Dielectric Constant of (Ba1-xSrx)(Mg1/3Ta2/3)O3Solid Solution and Its Relation to Structural Change

Journal	Data powered by TypesetMaterials Chemistry and Physics
Publisher	Data powered by TypesetElsevier Sequoia SA, Lausanne
ISSN	02540584
Open Access	No