Spherical Load Indentation in Submicron NiTiCu Shape Memory Thin Films


Nanoindentation with spherical tipped indenters provides a powerful technique to explore surface and thin film mechanical properties through the application of Hertzian contact mechanics. The full range of mechanical response can be obtained from elastic, through the yield point, to permanent deformation. In this study spherical indentation has been used for probing MBE-grown NiTiCu alloy thin films into superelasticity or stress-induced martensitic transformation. By this way, obstacles typically occurring related to the fabrication of freestanding films (film thickness < 1 µm) are avoided. The indentation measurements were performed starting from the parent austenite state. Notably, for loads as small as 0.5 mN, deformation appears to be completely reversible. As loading is increased (up to 5 mN) the indent becomes irreversible following local plastic deformation within the tip-specimen contact area. Using finite-element simulations the indentation data were converted into a stress-strain diagram aimed at simulating uniaxial tension load. Therefrom, the superelastic strain is estimated to be around 3%.


  1. 1.

    See, e.g., M. Kohl, D. Dittmann, E. Quandt, B. Winzek, S. Miyazaki, and D.M. Allen, Mater. Sci. Eng. A 273–275, 784 (1999).

    Google Scholar 

  2. 2.

    see, e.g., ACTUATOR 2004: Proceedings of the 9th International Conference on New Actuators, edited by H. Borgmann (Messe Bremen GmbH, Bremen, 2004).

  3. 3.

    E.G. Herbert, G.M. Pharr, W.C. Oliver, B.N. Lucas, and J.L. Hay, Thin Solid Films 398–399, 331 (2001), and references therein.

    Article  Google Scholar 

  4. 4.

    W. Ni, Y.T. Cheng, and D.S. Grummon, Appl. Phys. Lett. 82, 2811 (2003).

    CAS  Article  Google Scholar 

  5. 5.

    G.A. Shaw, D.S. Stone, A.D. Johnson, A.B. Ellis, and W.C. Crone, Appl. Phys. Lett. 83, 257 (2003).

    CAS  Article  Google Scholar 

  6. 6.

    X.G. Ma and K. Komvopoulos, Appl. Phys. Lett. 83, 3773 (2003).

    CAS  Article  Google Scholar 

  7. 7.

    R. Hassdorf, J. Feydt, R. Pascal, S. Thienhaus, M. Boese, T. Sterzl, B. Winzek, and M. Moske, Mater. Trans. 43, 933 (2002).

    CAS  Article  Google Scholar 

  8. 8.

    R. Hassdorf, J. Feydt, S. Thienhaus, M. Boese, and M. Moske, in SMST-2003: Proceedings of the International Conference on Shape Memory and Superelastic Technologies, edited by A.R. Pelton and T. Duerig (Menlo Park, Calif.: SMST Society, 2004) pp. 713–722.

  9. 9.

    T. Chudoba, N. Schwarzer, and F. Richter, Surf. Coat. Technol. 154, 140 (2002).

    CAS  Article  Google Scholar 

  10. 10.

    T. Chudoba and N. Schwarzer, ELASTICA 2.1, software demonstration package, copyright asmec GmbH, Rossendorf, Germany.

  11. 11.

    F. Auricchio, Int. J. Plasticity 17, 971 (2001).

    Article  Google Scholar 

  12. 12.

    Y.C. Shu and K. Bhattacharya, Acta mater. 46, 5457 (1998).

    CAS  Article  Google Scholar 

Download references


This work has been supported by the German Federal Ministry of Education and Research (BMBF) under contract no. 03N4031A. M.K. was also partly supported by the GAAV CR grant IAA 1075402.

Author information



Corresponding author

Correspondence to R. Hassdorf.

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Hassdorf, R., Feydt, J., Thienhaus, S. et al. Spherical Load Indentation in Submicron NiTiCu Shape Memory Thin Films. MRS Online Proceedings Library 841, R9.7 (2004). https://doi.org/10.1557/PROC-841-R9.7

Download citation