Strain, structure and electronic states in MBE grown (Nb, Ti)O 2 mixed rutile

S. A. Chambers, Y. Gao, S. Thevuthasan, S. Wen, K. L. Merkle, N. Shivaparan, R. J. Smith

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

We have grown and characterized epitaxial Nb xTi 1-xO 2 on TiO 2(110) and (100) for the purpose of investigating the role of chemically-inequivalent metal atoms on the thermal and photocatalytic properties of TiO 2. Our goal is to introduce, in a highly controlled fashion, a Group VA transition metal into the lattice of a Group IVA transition metal oxide without altering the crystallographic structure. So doing would alter the electronic structure in interesting and potentially useful ways by the addition of one valence electron per substituted metal atom. However, strain builds in the film as more Nb is added at a rate which depends on the crystallographic orientation of the growth direction. Films grown along (110) can accommodate Nb mole fractions as high as approx.0.3 without forming misfit dislocations, whereas those grown along (100) are limited to approx.10 at. % Nb. Nb-O bond lengths in Nb xTi 1-xO 2 are the same as Ti-O bond lengths in pure TiO 2 prior to the onset of dislocation formation. The extra 4d valence electron per Nb atom forms a nonbonding band which is degenerate with bonding states in the valence band region.

Original languageEnglish
Title of host publicationMaterials Research Society Symposium - Proceedings
EditorsW.W. Gerberich, H. Gao, J.E. Sundgren, S.P. Baker
Volume436
Publication statusPublished - 1996
Externally publishedYes
EventProceedings of the 1996 MRS Spring Meeting - San Francisco, CA, USA
Duration: 8 Apr 199612 Apr 1996

Other

OtherProceedings of the 1996 MRS Spring Meeting
CitySan Francisco, CA, USA
Period8/4/9612/4/96

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ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials

Cite this

Chambers, S. A., Gao, Y., Thevuthasan, S., Wen, S., Merkle, K. L., Shivaparan, N., & Smith, R. J. (1996). Strain, structure and electronic states in MBE grown (Nb, Ti)O 2 mixed rutile In W. W. Gerberich, H. Gao, J. E. Sundgren, & S. P. Baker (Eds.), Materials Research Society Symposium - Proceedings (Vol. 436)