Structural, micro-structural, optical and dielectric behavior of mullite ceramics
| Autor: | Bijaylaxmi Biswal, Dilip Kumar Mishra, Satyaprakash Narayan Das, Satyanarayan Bhuyan |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
Arrhenius equation
Materials science Process Chemistry and Technology Sintering Mullite Dielectric Conductivity Surfaces Coatings and Films Electronic Optical and Magnetic Materials symbols.namesake visual_art Materials Chemistry Ceramics and Composites visual_art.visual_art_medium symbols Dielectric loss Ceramic Composite material High-κ dielectric |
| Zdroj: | Ceramics International. 47:32252-32263 |
| ISSN: | 0272-8842 |
| DOI: | 10.1016/j.ceramint.2021.08.120 |
| Popis: | Mullite ceramics of two different compositions Al0·60Si0·40O and Al0·75Si0·25O have been synthesized by pyrophoric method followed by reaction sintering at 1050°C. The structural, micro-structural, optical, and dielectric characterization of mullite has been carried out through XRD, Raman, SEM, UV–Visible and dielectric studies. In this work, the synthesized mullite materials possess quite high dielectric constant value with negligible dielectric loss factor. The room temperature dielectric constant values for Al0·60Si0·40O and Al0·75Si0·25O stoichiometric mullites are found to be 110 and 2665 with a loss factor of 2.04 and 2.29 at 100 Hz frequency, which is comparatively high than the corresponding values of dielectric constants reported in previous literatures of mullite. The dielectric constant values for both the ceramics are very high (>104) for temperatures greater than 250°C. The room temperature dielectric constant (6.03 and 5.08, at 1 MHz), dielectric loss (0.07 and 0.05, at 1 MHz), electrical conductivity (1.5 × 10−5 S/m and 8.1 × 10−6 S/m, at 300 °C) results for Al0·60Si0·40O and Al0·75Si0·25O prove these ceramics suitable for electronics-related applications. The Arrhenius type conductivity, non-Debye type relaxation mechanism is confirmed from AC conductivity, complex impedance, and modulus study of these ceramics. These ceramics possess high optical band gap values of 3.46 eV and 3.36 eV for Al0·60Si0·40O and Al0·75Si0·25O, respectively which is suitable for using as electronic circuit packaging material or as a dielectric substrate material for any kind of storage devices. |
| Databáze: | OpenAIRE |
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