Correlation Between Tolerance Factor and Temperature Coefficient of Dielectric Constant of (Ba,Sr)(Zn1/3Ta2/3)O3 Dielectric Resonator
TL;DR: In this article, the effect of substitution of Sr at the A site of Ba(Zn1/3Ta2/3)O3 was investigated with respect to tolerance factor (t) which determines the degree of packing of A and B site ions of perovskite unit cell, with an intension to understand the correlation between the temperature dependent dielectric properties with structure.
Abstract: The effect of substitution of Sr at the A site of Ba(Zn1/3Ta2/3)O3 was investigated with respect to tolerance factor (t) which determines the degree of packing of A and B site ions of perovskite unit cell, with an intension to understand the correlation between the temperature dependent dielectric properties with structure. The investigation reveals that the Ba rich compositions with highly symmetric cubic phase exhibits negative variation of dielectric constant with temperature and the Sr rich compositions with distorted structure always show positive variation of dielectric constant with temperature. The profile of τe variation of all the compositions was scaled with respect of reduced temperature which exhibits an exact signature of τe variation with the compositions at room temperature. The observed mechanism was explained using Clausius Mossoti equation.
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TL;DR: In this article, the dielectric behavior and structure of the Sr(Zn1/3Nb2/3)O3•Ba (Zn 1/3 Nb 2/3 )O3 solid solution have been investigated with the intention of understanding the relationship between the structural changes and the temperature coefficient of the relative permittivity τe.
Abstract: The dielectric behavior and structure of the Sr(Zn1/3Nb2/3)O3‐Ba(Zn1/3Nb2/3)O3 solid solution have been investigated with the intention of understanding the relationship between the structural changes and the temperature coefficient of the relative permittivity τe. A correlation between the value of τe and the occurrence of O‐octahedra tilts has been established. The occurrence of ferroelastic domains and their influence on τe has also been investigated. It is proposed that the results obtained can be used to generalize about the structure‐property relationships in compounds of the same class.
362 citations
TL;DR: In this paper, a dense ceramic with an ordered perovskite structure with chemical formula Ba(Mg1/3Ta2/3)O3 is prepared, aiming at materials for a dielectric resonator with temperature-stable high-dielectric contsant and low loss at microwave frequency.
Abstract: A dense ceramic with an ordered perovskite structure with chemical formula Ba(Mg1/3Ta2/3)O3 is prepared, aiming at materials for a dielectric resonator with temperature-stable high dielectric contsant and low loss at microwave frequency. A small amount of Mn ion is doped to the sample to complete the sintering. The dielectric constant and unloaded Q are 25 and 16800 at 10.5 GHz respectively. The temperature coefficient of resonant frequency is estimated as 2.7 ppm/°C in the vicinity of room temperature. The value of Q we obtained is the highest among those reported so far on ceramics having a similar characteristic.
272 citations
TL;DR: In this paper, an attempt has been made to find a correlation between ionic parameters of ceramic materials and their complex permittivity at microwave frequencies, using the Fourier transform infrared reflectivity spectra in the 30-4000 cm−1 range.
Abstract: An attempt has been undertaken to find a correlation between ionic parameters of ceramic materials and their complex permittivity at microwave frequencies Ten Ba(B1/2’B1/2‘)O3 complex perovskite compounds (B’=Y3+, In3+, Nd3+, Gd3+; B‘=Nb5+, Ta5+ and B’=Mg2+, Cd2+, B‘=W6+) are compared in order to study the effect of ionic radii, mass, and valence state on dielectric properties Fourier transform infrared reflectivity spectra in the 30–4000 cm−1 range were measured and evaluated by means of Kramers–Kronig analysis and classical oscillator fit The data were extrapolated below the measured frequency range to estimate the intrinsic microwave losses The correlations between loss, permittivity, ionic size, mass, and effective charge and polar‐phonon mode parameters were investigated Ionic size was revealed to be the most important parameter, determining the tolerance factor of the structure packing and through this controlling the phonon frequencies and dampings as well as the extrapolated low‐frequency int
148 citations
TL;DR: In this paper, solid solution ceramics in the Ba(Zn1/3Nb2/3)O3(BZN) and SZN system have been studied with a view to finding materials for use as dielectric resonators at microwave frequency.
Abstract: Solid solution ceramics in the Ba(Zn1/3Nb2/3)O3(BZN)–Sr(Zn1/3Nb2/3)O3 (SZN) system have been studied with a view to finding materials for use as dielectric resonators at microwave frequency. The relative dielectric constant and the unloaded Q at 10 GHz are respectively 41 and 5400 for BZN, and 40 and 2000 for SZN. The temperature coefficient of the resonant frequency is estimated as 30 ppm/°C for BZN and -38 ppm/°C for SZN. The dielectric constant of 0.3 BZN–0.7 SZN ceramic is nearly independent of temperature, which gives a very small estimated temperature coefficient of the resonant frequency of -5 ppm/°C.
134 citations
123 citations