Abstract
We have observed both metallic and semiconducting behavior in epitaxial thin films of the metallic oxide CaRuO3 deposited under identical conditions on (100) SrTiO3 substrates of varying crystalline quality. X-ray diffraction studies showed that while semiconducting films with enlarged unit cells were obtained on single crystal SrTiO3 substrates, metallic films with lattice parameters close to the bulk material grew on poor crystalline quality SrTiO3 substrates. The films deposited on (100) LaAlO3 substrates consistently showed metallic behavior. Atomic force microscope images suggest that the semiconducting films had a coherent two dimensional nucleation. In contrast, three dimensional island-like incoherent growth was seen in the metallic films. It is believed that in the coherent films a strain induced substitution of the small Ru4+ cations by the larger Ca2+ cations occurs, breaking the conduction pathway within the three dimensional network of the RuO6 octahedra and leading to a metal-insulator transition. This unique phenomenon - which is not observed in bulk material - can be significant in technologically important epitaxial perovskite oxide heterostructures.
Original language | English (US) |
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Pages (from-to) | 199-204 |
Number of pages | 6 |
Journal | Materials Research Society Symposium - Proceedings |
Volume | 477 |
DOIs | |
State | Published - 1997 |
Externally published | Yes |
Event | Proceedings of the 1997 MRS Spring Meeting - San Francisco, CA, USA Duration: Apr 1 1997 → Apr 4 1997 |
All Science Journal Classification (ASJC) codes
- General Materials Science
- Condensed Matter Physics
- Mechanics of Materials
- Mechanical Engineering