Mechanics, Materials Science & Engineering, May 2017 – ISSN 2412-5954
Dielectric Loss Behavior of SrxZn1-xMnTiO5 (x = 0.1 to 0.9) Ceramics 18 M. Maddaiah1,a, T. Sofi Sarmash1, T. Vidya Sagar1, T. Subbarao1 1 – Ceramic Composite Lab, Dept. of Physics, S. K University, Anantapuramu, A.P., India a – venkateswararaoikp@gmail.com DOI 10.2412/mmse.66.93.675 provided by Seo4U.link
Keywords: ceramics, titanate, dielectric loss, absorbers, microwave devices.
ABSTRACT. SrxZn1-xMnTiO5 (x = 0.1 to 0.9) ceramic samples were prepared by conventional solid state reaction technique. The mixed powder was calcined in the temperature range of 1050-1150oC for 10 hours. Further, the pellets were sintered finally in the temperature range 1150-1250oC for 2 hours in a crucible. The samples are characterized for dielectric properties. Especially, the variation of dielectric loss as a function of temperature and composition is discussed. The achieved results show that at room temperature all the samples reveal the low loss values which are suitable for low noise and microwave device applications. On the other hand, at high temperature all the samples perform the absorber behavior as they express high dielectric loss values.
Introduction. Strontium manganese titanate compound is unique material revealing antiferrodistortive elastic property, polar dielectric and spin glass magnetic behavior simultaneously [1]. So far there is no through studies on the synthesis of SrxZn1-xMnTiO5 (x=0.1 to 0.9) by solid state diffusion method and characterization by structural, dielectric, electrical and thermal properties. The substitution of zinc and manganese ions to from (Zn, Mn) TiO3 solid solution, is adopted to improve the thermal stability and dielectric properties. Strontium titanate-based ceramics were widely used to fabricate some electronic components, such as grain boundary layer capacitors (GBLC) was fabricated [1], it has been shown to have a great many merits, such as high-capacitance, low dielectric loss, and small size for low-voltage circuitry [2-7]. This requires a dielectric material with both high relative tunability nr (E) = [έ (0) - έ (E)]/έ(0) (where έ (0) is the dielectric constant at zero field, and έ (E) is the dielectric constant under applied field E), and very low dielectric loss at microwave frequencies. High tenability offers a capability for broad-range adjustment of the working frequencies, and low loss provides low noise, high selectivity and compatibility with cryogenic electronics. Zinc titanate (ZnTiO3) has hexagonal structure of dielectric materials for microwave applications such as mobile telephones and satellite communication systems. High performance with low loss and stable temperature coefficient of resonance frequency (τf) is basic requirement of dielectric. Alexander Tkach, Paula M. Vilarinho and Andrei L. Kholkin [8] studied the microstructure–dielectric tunability relationship in Mn-doped strontium titanate ceramic samples were prepared by the conventional mixed oxide method. The grain size was found to differ marked between Sr1-xMnxTiO3 (variation from 20 to35 µm) and SrT1-yMnyO3 ceramics (much finer grains from 0.6 to 0.8 µm) were observed), without clear dependence on Mn content. In the recent literature Naidu et al. [2], [9], [10], [11], Kumar et al. [12] and Maddaiah et al. [1], [13] investigated the effect of various elements (La, Mg, Mn, Cu, Zn & Bi) on electrical properties such as dielectric constant, loss, thermoelectric power, ac-conductivity and dc-conductivity of SrTiO3 electro ceramic material. These researchers reported that the Cu-doped SrTiO3 shows highest dielectric constant at room temperature (RT) [9]. In addition, several researchers showed the addition of zinc improves the loss of ceramic materials [14], [15]. © 2017 The Authors. Published by Magnolithe GmbH. This is an open access article under the CC BY-NC-ND license http://creativecommons.org/licenses/by-nc-nd/4.0/
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