Rouahi, A., Kahouli, A., Challali, F., Besland, M. P., Vallee, C., Yangui, B., Salimy, S., Goullet, A. & Sylvestre, A. (2013) Impedance and electric modulus study of amorphous TiTaO thin films: highlight of the interphase effect. J. Phys. D-Appl. Phys. 46 065308.
Added by: Laurent Cournède (2016-03-10 21:23:31)
|Type de référence: Article
Numéro d'identification (ISBN etc.): 0022-3727
Clé BibTeX: Rouahi2013
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Mots-clés: Conductivity, dielectric-relaxation, improvement, insulator-metal capacitors, spectroscopy
Créateurs: Besland, Challali, Goullet, Kahouli, Rouahi, Salimy, Sylvestre, Vallee, Yangui
Collection: J. Phys. D-Appl. Phys.
Consultations : 1/386
Indice de consultation : 1%
Indice de popularité : 0.25%
The influence of phases and phase's boundaries of TiO2 and Ta2O5 in the dielectric and electric response of TiTaO (100 nm thick) elaborated by RF magnetron sputtering was highlighted by complex impedance spectroscopy. Dielectric and electric modulus properties were studied over a wide frequency range (0.1-10(5) Hz) and at various temperatures (-160 to 120 degrees C). The diagram of Argand (epsilon '' versus epsilon') shows the contribution of phases, phases' boundaries and conductivity effect on the electric response of TiTaO thin films. Moreover, the resistance of the material decreases when the temperature increases, thus the material exhibits a negative temperature coefficient of resistance. The electric modulus plot indicates the presence of two peaks of relaxation. The first relaxation process appears at low temperature with activation energy of about 0.22 eV and it is related to the first ionization energy of oxygen vacancies. The second relaxation process appears at high temperature with activation energy of about 0.44 eV. This second peak is attributed to the Maxwell-Wagner-Sillars relaxation. The plots of the complex dielectric modulus and the impedance as a function of frequency allow concluding to a localized relaxation due to the long-range conductivity in the TiTaO film.
Added by: Laurent Cournède