Nonlinear positive temperature coefficient of resistance of BaTiO[sub 3] film.

Autor: Okano, Motochika, Watanabe, Yukio, Cheong, Sang-Wook
Předmět:
Zdroj: Applied Physics Letters; 3/24/2003, Vol. 82 Issue 12, p1923, 3p, 6 Graphs
Abstrakt: Conductance decreasing with increasing temperature (T) above a characteristic T (T[sub 0]) is found in the reverse-diode characteristics of metal contacts on strained BaTiO[sub 3] epitaxial films. The conduction mechanisms below and above TO near the Curie temperature of the bulk BaTiO[sub 3] are distinctly different. Marked similarities to these characteristics are found in the surface conduction on BaTiO[sub 3] single crystal in a high vacuum. By comparing the observations with the positive temperature coefficient of resistance (PTCR) effect in ceramics, we suggest that the anomaly is regarded as a PTCR effect at metal/ferroelectric contact, and discuss the origin of the effect in thin films and single crystals. [ABSTRACT FROM AUTHOR]
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