1. Low-temperature dielectric response of NaTaO3 ceramics and films.
- Author
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Tkach, A., Almeida, A., Moreira, J. Agostinho, Perez de la Cruz, J., Romaguera-Barcelay, Y., and Vilarinho, P. M.
- Subjects
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DIELECTRIC relaxation , *CERAMICS , *MIXED oxide catalysts , *PERMITTIVITY , *ARRHENIUS equation , *POLARONS - Abstract
In this work, NaTaO3 ceramics are prepared by conventional mixed oxide method and NaTaO3 films are deposited by RF magnetron sputtering on Si/SiO2/TiO2/Pt substrates. The dielectric response of the obtained NaTaO3 ceramics and films is analyzed as a function of frequency and temperature. Between 1 kHz and 1 MHz, the dielectric permittivity of NaTaO3 ceramics is frequency independent and increases on cooling up to ∼324, which is the highest value ever reported for NaTaO3 ceramics. In contrast, NaTaO3 films exhibit a dielectric relaxation between ∼20 and 30 K, following the Arrhenius law with activation energy ∼51 meV and pre-exponential term ∼10-15 s and attributed to polaron hopping. [ABSTRACT FROM AUTHOR]
- Published
- 2012
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