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A high-resolution transmission electron microscopy study of defects in γ-Al2O3 nanorods

Published online by Cambridge University Press:  03 March 2011

W.F. Li ,
X.L. Ma ,
Y. Li ,
W.S. Zhang  and
Z.D. Zhang
W.F. Li*
Affiliation:
Shenyang National Laboratory for Materials Science, Institute of Metal Research, and International Center for Materials Physics, Chinese Academy of Sciences, Shenyang 110016, People’s Republic of China
X.L. Ma
Affiliation:
Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, People’s Republic of China
Y. Li
Affiliation:
Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, People’s Republic of China
W.S. Zhang
Affiliation:
Shenyang National Laboratory for Materials Science, Institute of Metal Research, and International Center for Materials Physics, Chinese Academy of Sciences, Shenyang 110016, People’s Republic of China
Z.D. Zhang
Affiliation:
Shenyang National Laboratory for Materials Science, Institute of Metal Research, and International Center for Materials Physics, Chinese Academy of Sciences, Shenyang 110016, People’s Republic of China
*
a) Address all correspondence to this author. e-mail: [email protected]
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Abstract

Surface and planar defect structures of γ-Al2O3 nanorods synthesized by the arc-discharge method were studied by means of high-resolution transmission electron microscopy and image simulation. Our investigation showed that there was a high number density of twins in the nanorods. We suggested a possible configuration of {111} twins in γ-Al2O3, and this model fit our experimental result well. In some nanorods, the ordering of nanotwins gave rise to a local hexagonal-like structure. The twinned nanorods were usually enclosed by {100} and {111} facets, and their growth direction was changed from 〈110〉 into 〈111〉. The surface structures of the nanorods confirmed that the {111}-type surface should be more stable.

Keywords

DefectsNanostructureTransmission electron microscopy (TEM)
Type
Articles
Information
Journal of Materials Research , Volume 22 , Issue 3 , March 2007 , pp. 595 - 602
Copyright
Copyright © Materials Research Society 2007

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References

REFERENCES

1Wilson, S.J.: Phase transformations and development of microstructure in boehmite-derived transition aluminas. Proc. Br. Ceram. Soc. 28, 281 (1979).Google Scholar
2Thornton, J.A. and Chin, J.: Structure and heat treatment characteristics of sputter-deposited alumina. Am. Ceram. Soc. Bull. 56, 504 (1977).Google Scholar
3Frieser, R.G.: Phase changes in thin reactively sputtered alumina films. J. Electrochem. Soc. 113, 357 (1966).CrossRefGoogle Scholar
4McPherson, R.: On the formation of thermally sprayed alumina coatings. J. Mater. Sci. 15, 3141 (1980).CrossRefGoogle Scholar
5Lippens, B.C. and de Boer, J.H.: Study of phase transitions during calcinations of aluminum hydroxides by selected area electron diffraction. Acta Crystallogr. 17, 1312 (1964).CrossRefGoogle Scholar
6Dragoo, A.L. and Diamond, J.J.: Transitions in vapor-deposited alumina from 300 °C to 1200 °C. J. Am. Ceram. Soc. 50, 568 (1967).CrossRefGoogle Scholar
7Rooksby, H.P. and Rooymans, C.J.M.: The formation and structure of delta alumina. Clay Min. Bull. 4, 234 (1961).CrossRefGoogle Scholar
8Lux, B., Colombier, C., Altena, H., and Stjernberg, K.: Preparation of alumina coatings by chemical vapor deposition. Thin Solid Films 138, 49 (1986).CrossRefGoogle Scholar
9Chatfield, C., Lindstrom, J.N., and Stjernberg, M.E.: Microstructure of CVD-Al2O3. J. Phys. E.: Sci. Instrum. C5, 377 (1989).Google Scholar
10de Santos, H. Souza, Kiyohara, P.K., and de Santos, P.H. Souza: Thermal transformation of synthetic euhedral and fibrillar crystals of boehmite into aluminas. Mater. Res. Bull. 31, 799 (1996).CrossRefGoogle Scholar
11Levin, I. and Brandon, D.G.: A new metastable alumina polymorph with monoclinic symmetry. Philos. Mag. Lett. 77, 117 (1998).CrossRefGoogle Scholar
12Tsybulya, S.V. and Kryukova, G.N.: New x-ray powder diffraction data on delta-Al2O3. Powder Diffr. 18, 309 (2003).CrossRefGoogle Scholar
13Fang, X.S., Ye, C.H., Zhang, L.D., and Xie, T.: Twinning-mediated growth of Al2O3 nanobelts and their enhanced dielectric responses. Adv. Mater. 17, 1661 (2005).CrossRefGoogle Scholar
14Li, W.F., Ma, X.L., Zhang, W.S., Zhang, W., Li, Y., and Zhang, Z.D.: Synthesis and characterization of γ-alumina nanorods. Phys. Status Solidi A 203, 294 (2006).CrossRefGoogle Scholar
15Li, W.F., Ma, X.L., Li, Y., Zhang, W.S., Zhang, W., and Zhang, Z.D.: Stacking faults and polymorphs in alumina nanorods. Philos. Mag. 85, 3809 (2005).CrossRefGoogle Scholar
16Dong, X.L., Zhang, Z.D., Xiao, Q.F., Zhao, X.G., Chuang, Y.C., Jin, S.R., Sun, W.M., Li, Z.J., Zheng, Z.X., and Yang, H.: Characterization of ultrafine gamma-Fe(C), alpha-Fe(C) and Fe3C particles synthesized by arc-discharge in methane. J. Mater. Sci. 33, 1915 (1998).CrossRefGoogle Scholar
17Zhang, Z.D., Zheng, J.G., Škorvánek, I., Wen, G.H., Kováč, J., Wang, F.W., Yu, J.L., Li, Z.J., Dong, X.L., Jin, S.R., Liu, W., and Zhang, X.X.: Shell/core structure and magnetic properties of carbon-coated Fe-Co(C) nanocapsules. J. Phys.: Condens. Matter 13, 1921 (2001).Google Scholar
18Ealet, B., Elyakhlouffi, M.H., Gillet, E., and Ricci, M.: Electronic and crystallographic structure of γ-alumina thin-films. Thin Solid Films 250, 92 (1994).CrossRefGoogle Scholar
19Jayaram, V. and Levi, C.G.: The structure of δ-alumina evolved from the melt and the γ to δ transformation. Acta Metall. 37, 569 (1989).CrossRefGoogle Scholar
20Lee, M.H., Cheng, C.F., Heine, V., and Klinowski, J.: Distribution of tetrahedral and octahedral Al sites in gamma alumina. Chem. Phys. Lett. 265, 673 (1997).CrossRefGoogle Scholar
21Wang, Y.G., Bronsveld, P.M., and DeHosson, J.T.M.: Ordering of octahedral vacancies in transition aluminas. J. Am. Ceram. Soc. 81, 1655 (1998).CrossRefGoogle Scholar
22Cart, C.B. and Elgat, Z.: Twin boundaries parallel to the common-{111} plane in spinel. Philos. Mag. A. 55, 1 (1987).Google Scholar
23Wilson, S.J.: The dehydration of boehmite, γ-AlOOH, to γ-Al2O3. J. Solid State Chem. 30, 247 (1979).CrossRefGoogle Scholar
24Chou, T.C. and Nieh, T.G.: Nucleation and concurrent anomalous grain growth of α-Al2O3 during γ→α phase transformation. J. Am. Ceram. Soc. 74, 2270 (1991).CrossRefGoogle Scholar
25Levin, I. and Brandon, D.: Metastable alumina polymorphs: Crystal structures and transition sequences. J. Am. Ceram. Soc. 81, 1995 (1998).CrossRefGoogle Scholar
26Blonski, S. and Garofalini, S.H.: Molecular-dynamics simulation of α-alumina and γ-alumina surfaces. Surf. Sci. 295, 263 (1993).CrossRefGoogle Scholar
27Iijima, S.: Electron microscopy of small particles. J. Electron Microsc. (Tokyo) 34, 249 (1985).Google Scholar
28Wang, Z.L., Mohamed, M.B., Link, S., and El-Sayed, M.A.: Crystallographic facets and shapes of gold nanorods of different aspect ratios. Surf. Sci. 440, L809 (1999).CrossRefGoogle Scholar