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Heterogeneous dislocation nucleation from surfaces and interfaces as governing plasticity mechanism in nanoscale metals

  • Andrew T. Jennings (a1) and Julia R. Greer (a1)

We report the results of constant strain rate experiments on electroplated, single crystalline copper pillars with diameters between 75 and 525 nm. At slow strain rates, 10−3 s−1, pillar diameters with 150 nm and above show a size-dependent strength similar to previous reports. Below 150 nm, we find that the size effect vanishes as the strength transitions to a relatively size-independent regime. Strain rate sensitivity and activation volume are determined from uniaxial compression tests at different strain rates and corroborate a deformation mechanism change. These results are discussed in the framework of recent in situ transmission electron microscopy experiments observing two distinct deformation mechanisms in pillars and thin films on flexible substrates: partial dislocation nucleation from stress concentrations in smaller structures and single arm source operation in larger samples. Models attempting to explain these different size-dependent regimes are discussed in relation to these experiments and existing literature revealing further insights into the likely small-scale deformation mechanisms.

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1.Taylor G.I.: Plastic strain in metals. J. Inst. Met. 62, 307 (1938).
2.Hall E.O.: The deformation and ageing of mild steel. 3. Discussion of results. Proc. Phys. Soc. London, Sect. B 64, 747 (1951).
3.Petch N.J.: The cleavage strength of polycrystals. J. Iron Steel Inst. 174, 25 (1953).
4.Dehm G.: Miniaturized single-crystalline fcc metals deformed in tension: New insights in size-dependent plasticity. Prog. Mater. Sci. 54, 664 (2009).
5.Uchic M.D., Shade P.A., and Dimiduk D.M.: Plasticity of micrometer-scale single crystals in compression. Annu. Rev. Mater. Res. 39, 361 (2009).
6.Kraft O., Gruber P., Mönig R., and Weygand D.: Plasticity in confined dimensions. Annu. Rev. Mater. Res. 40, 293 (2010).
7.Greer J.R. and De Hosson J.T.M.: Review: Plasticity in small-sized metallic systems: Intrinsic versus extrinsic size effect. Prog. Mater. Sci. 56, 654 (2011).
8.Nix W.D., Greer J.R., Feng G., and Lilleodden E.T.: Deformation at the nanometer and micrometer length scales: Effects of strain gradients and dislocation starvation. Thin Solid Films 515, 3152 (2007).
9.Dimiduk D.M., Uchic M.D., and Parthasarathy T.A.: Size-affected single-slip behavior of pure nickel microcrystals. Acta Mater. 53, 4065 (2005).
10.Uchic M.D., Dimiduk D.M., Florando J.N., and Nix W.D.: Sample dimensions influence strength and crystal plasticity. Science 305, 986 (2004).
11.Greer J.R., Oliver W.C., and Nix W.D.: Size dependence of mechanical properties of gold at the micron scale in the absence of strain gradients. Acta Mater. 53, 1821 (2005).
12.Volkert C.A. and Lilleodden E.T.: Size effects in the deformation of sub-micron Au columns. Philos. Mag. 86, 5567 (2006).
13.Gruber P.A., Solenthaler C., Arzt E., and Spolenak R.: Strong single-crystalline Au films tested by a new synchrotron technique. Acta Mater. 56, 1876 (2008).
14.Oh S.H., Legros M., Kiener D., Gruber P., and Dehm G.: In situ TEM straining of single crystal Au films on polyimide: Change of deformation mechanisms at the nanoscale. Acta Mater. 55, 5558 (2007).
15.Parthasarathy T.A., Rao S.I., Dimiduk D.M., Uchic M.D., and Trinkle D.R.: Contribution to size effect of yield strength from the stochastics of dislocation source lengths in finite samples. Scr. Mater. 56, 313 (2007).
16.Rao S., Dimiduk D., Tang M., Parthasarathy T., Uchic M., and Woodward C.: Estimating the strength of single-ended dislocation sources in micron-sized single crystals. Philos. Mag. 87, 4777 (2007).
17.Rao S.I., Dimiduk D.M., Parthasarathy T.A., Uchic M.D., Tang M., and Woodward C.: Athermal mechanisms of size-dependent crystal flow gleaned from three-dimensional discrete dislocation simulations. Acta Mater. 56, 3245 (2008).
18.Norfleet D.M., Dimiduk D.M., Polasik S.J., Uchic M.D., and Mills M.J.: Dislocation structures and their relationship to strength in deformed nickel microcrystals. Acta Mater. 56, 2988 (2008).
19.von Blanckenhagen B., Arst E., and Gumbsch P.: Discrete dislocation simulation of plastic deformation in metal thin films. Acta Mater. 52, 773 (2004).
20.Tang H., Schwarz K.W., and Espinosa H.D.: Dislocation escape-related size effects in single-crystal micropillars under uniaxial compression. Acta Mater. 55, 1607 (2007).
21.Tang H., Schwarz K.W., and Espinosa H.D.: Dislocation-source shutdown and the plastic behavior of single-crystal micropillars. Phys. Rev. Lett. 100, 185503 (2008).
22.Weygand D., Poignant M., Gumbsch P. and Kraft O.: Three-dimensional dislocation dynamics simulation of the influence of sample size on the stress-strain behavior of fcc single-crystalline pillars. Mater. Sci. Eng., A 48384, 188 (2008).
23.Senger J., Weygand D., Gumbsch P., and Kraft O.: Discrete dislocation simulations of the plasticity of micro-pillars under uniaxial loading. Scr. Mater. 58, 587 (2008).
24.Oh S.H., Legros M., Kiener D., and Dehm G.: In situ observation of dislocation nucleation and escape in a submicrometre aluminium single crystal. Nat. Mater. 8, 95 (2009).
25.Jennings A.T., Li J., and Greer J.R.: Emergence of strain rate sensitivity in Cu nano-pillars: Transition from dislocation multiplication to dislocation nucleation. Acta Mater. 59, 5627 (2011).
26.Richter G., Hillerich K., Gianola D.S., Mönig R., Kraft O., and Volkert C.A.: Ultrahigh strength single crystalline nanowhiskers grown by physical vapor deposition. Nano Lett. 9, 3048 (2009).
27.Zheng H., Cao A., Weinberger C., Huang J.Y., Du K., Wang J., Ma Y., Xia Y., and Mao S.X.: Discrete plasticity in sub-10-nm-sized gold crystals. Nat. Commun. 1, 144 (2010).
28.Zhu T., Li J., Samanta A., Leach A., and Gall K.: Temperature and strain-rate dependence of surface dislocation nucleation. Phys. Rev. Lett. 100, 025502 (2008).
29.Deng C. and Sansoz F.: Size-dependent yield stress in twinned gold nanowires mediated by site-specific surface dislocation emission. App. Phys. Lett. 95, 091914 (2009).
30.Burek M.J. and Greer J.R.: Fabrication and microstructure control of nanoscale mechanical testing specimens via electron beam lithography and electroplating. Nano Lett. 10, 69 (2010).
31.Jennings A.T., Burek M.J., and Greer J.R.: Microstructure versus size: Mechanical properties of electroplated single crystalline Cu nanopillars. Phys. Rev. Lett. 104, 135503 (2010).
32.Jennings A.T. and Greer J.R.: Tensile deformation of electroplated copper nanopillars. Philos. Mag. 91, 1108 (2011).
33.Bei H., Shim S., George E.P., Miller M.K., Herbert E.G., and Pharr G.M.: Compressive strengths of molybdenum alloy micro-pillars prepared using a new technique. Scr. Mater. 57, 397 (2007).
34.Bei H., Shim S., Pharr G.M., and George E.P.: Effects of pre-strain on the compressive stress-strain response of Mo-alloy single-crystal micropillars. Acta Mater. 56, 4762 (2008).
35.Shim S., Bei H., Miller M.K., Pharr G.M., and George E.P.: Effects of focused-ion-beam milling on the compressive behavior of directionally solidified micropillars and the nanoindentation response of an electropolished surface. Acta Mater. 57, 503 (2009).
36.Buzzi S., Dietiker M., Kunze K., Spolenak R., and Loffler J.F.: Deformation behavior of silver submicrometer-pillars prepared by nanoimprinting. Philos. Mag. 89, 869 (2009).
37.Dietiker M., Buzzi S., Pigozzi G., Loffler J.F., and Spolenak R.: Deformation behavior of gold nano-pillars prepared by nanoimprinting and focused-ion-beam milling. Acta Mater. 59, 2180 (2011).
38.Kiener D. and Minor A.M.: Source-controlled yield and hardening of Cu(100) studied by in situ transmission electron microscopy. Acta Mater. 59, 1328 (2011).
39.Lowry M.B., Kiener D., LeBlanc M.M., Chisholm C., Florando J.N., Morris J.W., and Minor A.M.: Achieving the ideal strength in annealed molybdenum nanopillars. Acta Mater. 58, 5160 (2010).
40.Greer J.R., Jang D.C., Kim J.Y., and Burek M.J.: Emergence of new mechanical functionality in materials via size reduction. Adv. Funct. Mater. 19, 2880 (2009).
41.Kocks U.F., Argon A.S., and Ashby M.F.: Thermodynamics and kinetics of slip. Prog. Mater. Sci. 19, 1 (1975).
42.Nix W.D. and Lee S.W.: Micro-pillar plasticity controlled by dislocation nucleation at surfaces. Philos. Mag. 91, 1084 (2011).
43.Ng K.S. and Ngan A.H.W.: Stochastic theory for jerky deformation in small crystal volumes with pre-existing dislocations. Philos. Mag. 88, 677 (2008).
44.Brenner S.S.: Tensile strength of whiskers. J. Appl. Phys. 27, 1484 (1956).
45.Lu Y., Huang J.Y., Wang C., Sun S.H., and Lou J.: Cold welding of ultrathin gold nanowires. Nat. Nanotechnol. 5, 218 (2010).
46.Shan Z.W., Mishra R.K., Syed Asif S.A., Warren O.L., and Minor A.M.: Mechanical annealing and source-limited deformation in submicrometre-diameter Ni crystals. Nat. Mater. 7, 115 (2008).
47.Weinberger C.R. and Cai W.: Surface-controlled dislocation multiplication in metal micropillars. Proc. Natl. Acad. Sci. USA 105, 14304 (2008).
48.Nix W.: Mechanical properties of thin films. Metall. Mater. Trans. A 20, 2217 (1989).
49.Freund L.B.: The stability of a dislocation threading a strained layer on a substrate. J. Appl. Mech. 54, 553 (1987).
50.Greer J.R. and Nix W.D.: Nanoscale gold pillars strengthened through dislocation starvation. Phys. Rev. B 73, 245410 (2006).
51.Chen M.W., Ma E., Hemker K.J., Sheng H.W., Wang Y.M., and Cheng X.M.: Deformation twinning in nanocrystalline aluminum. Science 300, 1275 (2003).
52.Aubry S., Kang K., Ryu S., and Cai W.: Energy barrier for homogeneous dislocation nucleation: Comparing atomistic and continuum models. Scr. Mater. 64, 1043 (2011).
53.Beltz G.E. and Freund L.B.: On the nucleation of dislocations at a crystal surface. Phys. Status Solidi B 180, 303 (1993).
54.Weinberger C.R., Jennings A.T., Kang K. and Greer J.R.: Atomistic simulations and continuum modeling of dislocation nucleation and strength in gold nanowires. J. Mech. Phys. Solids (2011, doi:10.1016/j.jmps.2011.09.010).
55.Estrin Y., Kim H.S., and Nabarro F.R.N.: A comment on the role of Frank-Read sources in plasticity of nanomaterials. Acta Mater. 55, 6401 (2007).
56.Shemenski R.M.: Thermal activation of a dislocation source. ASM Trans. Q. 58, 360 (1965).
57.Conrad H.: Grain size dependence of the plastic deformation kinetics in Cu. Mater. Sci. Eng., A 341, 216 (2003).
58.Zhu T. and Li J.: Ultra-strength materials. Prog. Mater. Sci. 55, 710 (2010).
59.Li X.Y., Wei Y.J., Lu L., Lu K., and Gao H.J.: Dislocation nucleation governed softening and maximum strength in nano-twinned metals. Nature 464, 877 (2010).
60.Van Swygenhoven H., Derlet P.M., and Froseth A.G.: Stacking fault energies and slip in nanocrystalline metals. Nat. Mater. 3, 399 (2004).
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