lattice expansion, covalency enhancement, nanocrystals
Lattice variations and bonding characteristics in rutile TiO2 nanocrystals were examined by x-ray diffraction and x-ray photoelectron spectroscopy. With a reduction in the physical dimensions, rutile TiO2 nanocrystals show a linear lattice expansion and an anomalous covalency enhancement in apparent contradiction to the ionicity increase in BaTiO3 and CuO nanocrystals as reported recently by S. Tsunekawa et al. [Phys. Rev. Lett. 2000, 85, 3440] and V. R. Palkar et al. [Phys. Rev. B 1996, 53, 2167]. A surface defect dipole model is proposed to explain these physical phenomena in terms of the strong interactions among the surface dipoles that produce an increased negative pressure. The covalency enhancement is interpreted according to the critical properties of the increased TiO bond lengths in the expanded lattice
Original Publication Citation
Li, Guangshe, Juliana B. Goates, Brian F. Woodfield, and Liping Li."Evidence of linear lattice expansion and covalency enhancement in rutile TiO[sub 2] nanocrystals." Applied Physics Letters 85 (24): 259-261.
BYU ScholarsArchive Citation
Li, Guangshe; Boerio-Goates, Juliana; Woodfield, Brian F.; and Li, Liping, "Evidence of linear lattice expansion and covalency enhancement in rutile TiO2 nanocrystals" (2004). All Faculty Publications. 416.
Physical and Mathematical Sciences
Chemistry and Biochemistry
© 2004 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. The following article appeared in Applied Physics Letters and may be found at http://link.aip.org/link/?APPLAB/85/2059/1
Copyright Use Information