Abstract
Nb-doped semiconductive SrTiO3 film and Bi and Nb co-added SrTiO3 film were grown on (001) MgO sub-strates by metal-organic chemical vapor deposition (MOCVD). The (001)-oriented SrTiO3 phase was grown epitaxially with cube-on-cube structure in relation to the MgO substrate. In the ease of the Nb-doped SrTiO3 film, the film exhibited a semiconductive nature with a low electrical resistivity (0.11 Ω · cm) that is three orders of magnitude lower than that in bulk SrTiOa ceramics by adding a much higher Nb addition (1.6-3.5 mol%). Most of the added Nb is thought to substitute for the Ti4+ as valence 4+, as suggested by the dependency of the cell volume change. In the case of Bi and Nb co-added SrTiO3 film, the lattice parameter was somewhat increased with the addition of Bi, but the amount of Bi was undetectable. The addition of Bi did not produce a thin film with nonlinear electrical resistivity. Introducing a SrO seed layer with ∼2 nm thickness onto (001) MgO substrate produced weak nonlinear I-V (varistor) properties. It might be thought that the grain boundary between the two kinds of in-plane oriented grains, i.e., 45° rotating and cube-on-cube grains, acts as a barrier against varistor characteristics.
Original language | English |
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Pages (from-to) | 416-420 |
Number of pages | 5 |
Journal | Journal of the Ceramic Society of Japan |
Volume | 110 |
Issue number | 1281 |
DOIs | |
Publication status | Published - 2002 May |
Externally published | Yes |
Keywords
- LaAlO
- MOCVD
- Metal-organic chemical vapor deposition
- MgO
- Nb and Bi co-added
- SrTiO
- Thin film
- Varistor
ASJC Scopus subject areas
- Ceramics and Composites
- Chemistry(all)
- Condensed Matter Physics
- Materials Chemistry