STRUCTURAL CHARACTERISTICS & DIELECTRIC PROPERTIES OF TANTALUM OXIDE DOPED BARIUM TITANATE BASED MATERIALS
Journal Title: Materials Engineering - Materialove inzinierstvo (MEMI) - Year 2013, Vol 20, Issue 1
Abstract
In this research, the causal relationship between the dielectric properties and the structural characteristics of 0.5 & 1.0 mole % Ta2O5 doped BaTiO[sub]3[/sub] based ceramic materials were investigated under different sintering conditions. Dielectric properties and microstructure of BaTio3 ceramics were significantly influenced by the addition of a small amount of Ta[sub]2[/sub]O[sub]5[/sub]. Dielectric properties were investigated by measuring the dielectric constant (k) as a function of temperature and frequency. Percent theoretical density (%TD) above 90 % was achieved for 0.5 and 1.0 mole %Ta[sub]2[/sub]O[sub]5[/sub] doped BaTiO[sub]3[/sub]. It was observed that the grain size decreased markedly above a doping concentration of 0.5 mole % Ta[sub]2[/sub]O[sub]5[/sub]. Although fine grain size down to 200 - 300 nm was attained, grain sizes in the range of 1-1.8µm showed the most alluring properties. The fine-grain quality and high density of the Ta[sub]2[/sub]O[sub]5[/sub] doped BaTiO[sub]3[/sub] ceramic resulted in tenfold increase of dielectric constant. Stable value of dielectric constant as high as 13000 - 14000 was found in the temperature range of 55 to 80 °C, for 1.0 mole % Ta2O5 doped samples with corresponding shift of Curie point to ~82 °C. Experiments divulged that incorporation of a proper content of Ta[sub]2[/sub]O[sub]5[/sub] in BaTiO[sub]3[/sub] could control the grain growth, shift the Curie temperature and hence significantly improve the dielectric property of the BaTiO[sub]3[/sub] ceramics.
Authors and Affiliations
Rubayyat Mahbub, Md. Sazzad Hossain, Md. Fakhrul Islam
Keywords
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