Influence of Cu Addition on the Structure and Dielectric Properties of CaTiO3 | ||
| Egyptian Journal of Solids | ||
| Article 6, Volume 26, Issue 2, 2003, Pages 175-183 PDF (260.02 K) | ||
| DOI: 10.21608/ejs.2003.150150 | ||
| Abstract | ||
| The structure characterization and dielectric properties were studied for a series of copper-doped calcium titanates, Ca100-x Cux TiO3, where x =[Cu/(Cu+Ca)]% = 0.5, 1.0, 3.0 and 5.0, prepared by the conventional solid state reaction method. X-ray diffraction analyses indicate that all samples belong to the orthorhombic system. Cu addition results in non linear variation of lattice parameters. As the Cu concentration increases up to x ≅ 3.0, the lattice parameters (a, b and c) as well as the unit cell volume show an increase followed by a decrease with higher concentration of Cu (x > 3). Variation of lattice parameters with Cu doping is discussed based on the relative ionic radius and the filling of the present vacancies. Variation of the dielectric constant (ε`) and dielectric loss (ε``) with frequency (100 -2x106 Hz) at different temperatures (300, 400, 500 and 600 K) was studied. It showed that pure CaTiO3 has the highest ε` value (1200) at low frequency. On the other hand, ε` and ε`` fall to lower values by the addition of CuO. By increasing the frequency up to 50 kHz, the measured ε` decreased for all the samples. At low frequencies, rapid increase of ε` and ε`` is observed with raising the temperature of measurements. At higher frequencies, the dielectric properties are independent on both the frequency and temperature. | ||
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