Abstract
The temperature and frequency dependence of dielectric properties of A-site lower valence cation Na-doped Barium strontium titanate (Ba1-xNax)0.9Sr0.1TiO3 - (x = 0.01, 0.03, 0.05, 0.08, 0.1, 0.15, 0.2 and 0.3) ceramics have been investigated up to 450 C from 100 Hz to 1 MHz. Other than dielectric properties at low temperature, the relaxation behavior above 150 C for all the compositions was observed with broad dielectric peaks (T), tan (T) and (f). The universal dielectric response associated with the activation energy of 0.79-0.98 eV and complex impedance properties indicate that with the increasing of Na, the concentration of oxygen vacancies inhabiting grain boundary increases and under thermal stimulation the tunneling effect of oxygen vacancies strengthens, which dominate for the relaxation at high temperatures.
Original language | English |
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Pages (from-to) | 14-18 |
Number of pages | 5 |
Journal | Solid State Ionics |
Volume | 269 |
DOIs | |
State | Published - Jan 2015 |
Keywords
- Dielectric relaxation
- Grain boundary
- Na-doped Barium strontium titanate
- Oxygen vacancies