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Deformation micromechanisms of ZnO single crystals as determined from spherical nanoindentation stress–strain curves

Published online by Cambridge University Press:  31 January 2011

Sandip Basu*
Affiliation:
Department of Materials Science and Engineering, Drexel University, Philadelphia, Pennsylvania 19104
Michel W. Barsoum
Affiliation:
Department of Materials Science and Engineering, Drexel University, Philadelphia, Pennsylvania 19104
*
a)Address all correspondence to this author.e-mail: sandip.basu@gmail.com
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Abstract

In this work, instrumented nanoindentation experiments with two spherical tips with radii of 13.5 and 1 μm were used to explore the deformation behavior of ZnO single crystals with two orientations, C (basal) and A (prism). By converting the nanoindentation load–displacement data to stress–strain curves, we show that the main reason the hardening rates are higher for the C plane than they are for the A plane is the activation of dislocations—with widely different flow stresses—on different sets of slip planes. For the former, glide occurs on basal planes as well as pyramidal planes; for the latter, glide occurs predominantly on basal planes. The C plane is roughly twice as hard as the A plane, probably due to the orientation of basal planes with respect to the indentation axis. A Weibull statistical analysis of the pop-in stresses indicates that the inherent defect concentration at or near the surface is the main factor for the initiation of plastic deformation. The strain energy released when the pop-ins occur determines their extent. The elastic moduli values, determined by Berkovich nanoindentation, are 135 ± 3 GPa and 144 ± 4 GPa for the C and A planes, respectively. In the C orientation repeated indentations to the same stress result in fully reversible hysteretic loops that are attributed to the formation of incipient kink bands.

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Articles
Copyright
Copyright © Materials Research Society 2007

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References

REFERENCES

1Kucheyev, S.O., Bradby, J.E., Williams, J.S., Jagadish, C.Swain, M.V.: Mechanical deformation of single-crystal ZnO. App. Phys. Lett. 80, 956 2002CrossRefGoogle Scholar
2Ozgur, U., Alivov, Y.I., Liu, C., Teke, A., Reshchikov, M.A., Dogan, S., Avrutin, V., Cho, S.J.Morkoc, H.: A comprehensive review of ZnO materials and devices. J. App. Phys. 98, 041301 2005CrossRefGoogle Scholar
3Ahearn, J.S., Mills, J.J.Westwood, A.R.C.: Effect of electrolyte pH and bias voltage on the hardness of the (0001) ZnO surface. J. Appl. Phys. 49, 96 1978CrossRefGoogle Scholar
4Prasad, S.V.Zabinski, J.S.: Tribological behavior of nanocrystalline zinc oxide films. Wear 203–204, 498 1997CrossRefGoogle Scholar
5Bradby, J.E., Kucheyev, S.O., Williams, J.S., Jagadish, C., Swain, M.V., Munroe, P.Phillips, M.R.: Contact-induced defect propagation in ZnO. App. Phys. Lett. 80, 4537 2002CrossRefGoogle Scholar
6Coleman, V.A., Bradby, J.E., Jagadish, C., Munroe, P., Heo, Y.W., Pearton, S.J., Norton, D.P., Inoue, M.Yano, M.: Mechanical properties of ZnO epitaxial layers grown on a- and c-axis sapphire. App. Phys. Lett. 86, 203105 2005CrossRefGoogle Scholar
7Coleman, V.A., Bradby, J.E., Jagadish, C.Phillips, M.R.: A comparison of the mechanical properties and the impact of contact induced in a and c-axis ZnO single crystals in Zinc Oxide and Related Materials edited by J. Christen, C. Jagadish, D.C. Look, T. Yao, and F. Bertram (Mater. Res. Soc. Symp. Proc. 957Warrendale, PA 2007 0957-K07-17Google Scholar
8Barsoum, M.W., Murugaiah, A., Kalidindi, S.R.Zhen, T.: Kinking nonlinear elastic solids, nanoindentations and geology. Phys. Rev. Lett. 92, 255508-1 2004CrossRefGoogle ScholarPubMed
9Barsoum, M.W., Murugaiah, A., Kalidindi, S.R.Gogotsi, Y.: Kink bands, nonlinear elasticity and nanoindentations in graphite. Carbon 42, 1435 2004CrossRefGoogle Scholar
10Basu, S., Barsoum, M.W.Kalidindi, S.R.: Sapphire: A kinking nonlinear elastic solid. J. Appl. Phys. 99, 063501 2006CrossRefGoogle Scholar
11Basu, S., Moseson, A.Barsoum, M.W.: On the determination of spherical nanoindentation stress–strain curves. J. Mater. Res. 21, 2628 2006CrossRefGoogle Scholar
12Murugaiah, A., Barsoum, M.W., Kalidindi, S.R.Zhen, T.: Spherical nanoindentations in Ti3SiC2. J. Mater. Res. 19, 1139 2004CrossRefGoogle Scholar
13Johnson, K.L.: Contact Mechanics Cambridge University Press Cambridge, UK 1985CrossRefGoogle Scholar
14Herbert, E.G., Pharr, G.M., Oliver, W.C., Lucas, B.N.Hay, J.L.: On the measurement of stress-strain curves by spherical indentation. Thin Solid Films 398–399, 331 2001CrossRefGoogle Scholar
15Field, J.S.Swain, M.V.: Determining the mechanical-properties of small volumes of material from submicrometer spherical indentations. J. Mater. Res. 10, 101 1995CrossRefGoogle Scholar
16Tabor, D.: Hardness of Metals Clarendon Oxford, UK 1951Google Scholar
17Bradby, J.E., Williams, J.S.Swain, M.V.: Pop-in events induced by spherical indentation in compound semiconductors. J. Mater. Res. 19, 380 2004CrossRefGoogle Scholar
18Barsoum, M.W., Zhen, T., Zhou, A., Basu, S.Kalidindi, S.R.: Microscale modeling of kinking nonlinear elastic solids. Phys. Rev. B 71, 134101 2005CrossRefGoogle Scholar
19Barsoum, M.W., Zhen, T., Kalidindi, S.R., Radovic, M.Murugahiah, A.: Fully reversible, dislocation-based compressive deformation of Ti3SiC2 to 1 GPa. Nat. Mater. 2, 107 2003CrossRefGoogle ScholarPubMed
20Basu, S., Barsoum, M.W., Williams, A.D.Moustakas, T.D.: Spherical nanoindentation and deformation mechanisms in free-standing GaN films. J. App. Phys.,101, 083522-1 2007CrossRefGoogle Scholar
21Frank, F.C.Stroh, A.N. On the theory of kinking. Proc. Phys. Soc., 65, 811 1952CrossRefGoogle Scholar
22Zhou, A.G., Barsoum, M.W., Basu, S., Kalidindi, S.R.El-Raghy, T.: Incipient and regular kink bands in dense and porous Ti2AlC. Acta Mater. 54, 1631 2006CrossRefGoogle Scholar
23Coleman, V.A., Bradby, J.E., Jagadish, C.Phillips, M.R.: Observation of enhanced defect emission and excitonic quenching from spherically indented ZnO. App. Phys. Lett. 89, 082102 2006CrossRefGoogle Scholar
24Kooi, B.J., Poppen, R.J., Carvalho, N.J.M., DeHosson, J.T.M.Barsoum, M.W.: Ti3SiC2: A damage tolerant ceramic studied with nanoindentations and transmission electron microscopy. Acta Mater. 51, 2859 2003CrossRefGoogle Scholar
25Molina-Aldareguia, J.M., Emmerlich, J., Palmquist, J., Jansson, U.Hultman, L.: Kink formation around indents in laminated Ti3SiC2 thin-films studied in the nano scale. Scripta Mater. 49, 155 2003CrossRefGoogle Scholar