Rutherford backscattering and channeling studies of Mg and Fe diffusion at the interface of γ-Fe2O3(001)/MgO(001)
✍ Scribed by Thevuthasan, S.; Jiang, W.; McCready, D. E.; Chambers, S. A.
- Publisher
- John Wiley and Sons
- Year
- 1999
- Tongue
- English
- Weight
- 225 KB
- Volume
- 27
- Category
- Article
- ISSN
- 0142-2421
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✦ Synopsis
We have investigated the crystalline quality of an epitaxially-grown Ðlm on MgO(001) substrate c-Fe 2 O 3 (001) along with Mg and Fe inter-di †usion using Rutherford backscattering spectrometry (RBS) and channeling experiments. The channeling e †ect in the Ðlm appears to be reduced compared to an ideal single crystal, with the minimum yield for Fe determined to be in the range 16-18% . Growth at a substrate temperature of 450 ÄC promotes limited Mg out-di †usion into the Ðlm. Subsequent appealing results in further Mg out-di †usion, which increases in extent with increasing temperature. A minimum of 4 at.% Mg was detected throughout the Ðlm at temperatures below the onset of Fe in-di †usion, which was found to be 800 ÄC. This impurity cation concentration is comparable to the native vacancy concentration in (4.8 at.% ), suggesting that Mg occupies cation c-Fe 2 O 3 vacancy sites, as already established by Auger electron di †raction measurements for this system. The Mg concentration in the Ðlm was 8 at.% , while the associated Fe concentration in the substrate was 3.4 at.% after annealing at 800 ÄC. Moreover, these cation impurities were uniformly distributed throughout the Ðlm and substrate, with the fraction of substitution in both cases > 90% at lower temperatures.