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  1. No Access

    Article

    Reply to: On the observation of photo-excitation effects in molecules using muon spin spectroscopy

    M. **gliang, K. Wang, P. Murahari, K. Yokoyama, J. S. Lord… in Nature Materials (2022)

  2. Article

    Open Access

    Easy computation of the Bayes factor to fully quantify Occam’s razor in least-squares fitting and to guide actions

    The Bayes factor is the gold-standard figure of merit for comparing fits of models to data, for hypothesis selection and parameter estimation. However, it is little-used because it has been considered to be su...

    D. J. Dunstan, J. Crowne, A. J. Drew in Scientific Reports (2022)

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  3. No Access

    Article

    Temporal map** of photochemical reactions and molecular excited states with carbon specificity

    Photochemical reactions are essential to a large number of important industrial and biological processes. A method for monitoring photochemical reaction kinetics and the dynamics of molecular excitations with ...

    K. Wang, P. Murahari, K. Yokoyama, J. S. Lord, F. L. Pratt, J. He… in Nature Materials (2017)

  4. No Access

    Article

    Physical Origin of a Size Effect in Nanoindentation

    We have reported results of nanoindentation using spherical indenters to observe the full indentation stress-strain curve. We observe the onset of plasticity in semiconductor strained-layer superlattices. Thes...

    A. J. Bushby, J. R. Downes, N. B. Jayaweera, P. Kidd… in MRS Online Proceedings Library (2011)

  5. No Access

    Article

    Slip distance model for the indentation size effect at the initiation of plasticity in ceramics and metals

    The indentation size effect, in which the contact pressure increases as the size of contact decreases, has been observed for many years for both spherical and pointed indenters. The concept of strain gradient ...

    A. J. Bushby, T. T. Zhu, D. J. Dunstan in Journal of Materials Research (2009)

  6. No Access

    Article

    Map** of the Initial Volume at the Onset of Plasticity in Nanoindentation

    Understanding the finite volume throughout which plastic deformation begins is necessary to understand the mechanics of small-scale deformation. In indentation using spherical indenters, conventional yield cri...

    T. T. Zhu, K. M. Y. P’ng, M. Hopkinson, A. J. Bushby… in MRS Online Proceedings Library (2008)

  7. No Access

    Article

    Size Effect in the Initiation of Plasticity for Ceramics in Nanoscale Contact Loading

    In nanoindentation, the plasticity size effect has been observed for several years, where a higher hardness is measured as indenter size decreases. In this paper, we report the size effect on the initiation of...

    T. T. Zhu, X. D. Hou, C. J. Walker, K. M Y. P’ng… in MRS Online Proceedings Library (2007)

  8. No Access

    Article

    Enhanced Raman signal of CH3 on carbon nanotubes

    We find that functionalized SWCNT and DWCNT’s (mainly double wall carbon nanotubes) in composites, DWCNTs under hydrostatic pressure and blue illuminated DWCNTs in methanol show the same up shift of the Raman ...

    A. Bassil, P. Puech, G. Landa, W. Bacsa, H. Hubel… in MRS Online Proceedings Library (2004)

  9. No Access

    Article

    Deformation of Small Volumes of Material Studied Using Strained-Layer Superlattice Structures

    Mechanical studies of semiconductor superlattices have shown that the onset of plastic deformation under an inhomogeneous stress is a process that takes place simultaneously across a finite volume of the order...

    K. M. Y. P’ng, A. J. Bushby, D. J. Dunstan in MRS Online Proceedings Library (2004)

  10. No Access

    Article

    Plasticity size effects in nanoindentation

    In conventional continuum mechanics, the yield behavior of a material is size independent. However, in nanoindentation, plasticity size effects have been observed for many years, where a higher hardness is mea...

    A. J. Bushby, D. J. Dunstan in Journal of Materials Research (2004)

  11. No Access

    Article

    Geometrical Contribution to Yield Strength in Small Volumes

    Critical thickness theory was developed to account for the ability of thin epitaxial metal and semiconductor layers to support high misfit or coherency strain. The thermodynamic equilibrium theory is correct, ...

    D. J. Dunstan, A. J. Bushby in MRS Online Proceedings Library (2004)

  12. No Access

    Article

    Coherency Strain and a New Yield Criterion

    We have studied the onset of plasticity in coherently-strained semiconductor superlattices, using nano-indentation with spherical indenter tips to observe the full stress-strain curve. The yield pressure is re...

    N. B. Jayaweera, J. R. Downes, D. J. Dunstan… in MRS Online Proceedings Library (2001)

  13. No Access

    Chapter

    Investigations of Semiconductor Band Structure Using High Pressure.

    Basic effects of pressure on semiconductors are the increase of direct band gap with the density of the crystal, the consequent band crossovers, and the increase in phonon frequencies. We briefly review experi...

    D. J. Dunstan in High Pressure Molecular Science (1999)

  14. No Access

    Chapter

    Experimental Techniques in the Diamond Anvil Cell

    The operating principles of diamond-anvil high pressure cells are reviewed, with particular attention to the implications for design and construction. The diamond culets and gasket generate the pressure, and t...

    D. J. Dunstan in High Pressure Molecular Science (1999)

  15. No Access

    Article

    Strain and strain relaxation in semiconductors

    Single-crystal semiconductor layers can be grown with large coherency strains. This review covers their standard elasticity theory and methods of measuring the strain. High-quality strained layers are thermody...

    D. J DUNSTAN in Journal of Materials Science: Materials in Electronics (1997)

  16. No Access

    Article

    Coherency Strain and High Strength at High Temperature

    We propose an athermal strengthening mechanism for high-temperature structural materials in which large coherency strains are built in to a layered structure in order to prevent dislocation mulitplication mech...

    M. E. Brenchley, D. J. Dunstan, P. Kidd, A. Kelly in MRS Online Proceedings Library (1996)

  17. No Access

    Chapter

    Applications of Diamond-Anvil Cells to Materials Science

    Diamond-anvil cells allow the study of condensed matter as the interatomic spacing is changed over a wide range. This causes both quantitative and qualititative changes in material properties. Semiconductors u...

    D. J. Dunstan in High Pressure Chemistry, Biochemistry and Materials Science (1993)

  18. No Access

    Chapter

    Recent Developments in Diamond-Anvil Cells

    Diamond-anvil cells have been simplified and miniaturised to the point where they can be added with little difficulty to a wide range of experiments. This allows high pressure, or the control of interatomic sp...

    D. J. Dunstan in High Pressure Chemistry, Biochemistry and Materials Science (1993)

  19. No Access

    Article

    Investigation of the band structure of the strained systems InGaAs/GaAs and InGaAs/AIGaAs by high-pressure photoluminescence

    InxGa1-xAs quantum wells grown pseudomorphically in GaAs and AlGaAs with values ofx up to 0.25 have been studied by photoluminescence under high hydrostatic pressure. We concentrate here on the pressure range whe...

    V. A. Wilkinson, A. D. Prins, D. J. Dunstan… in Journal of Electronic Materials (1991)

  20. No Access

    Chapter and Conference Paper

    ESR Study of Metastable Carriers in Hydrogenated Amorphous Silicon

    The Light induced ESR (LESR) signal in a-Si:H has been studied up to 104s after an excitation light pulse. The evolution of this meta-stable signal with temperature and with infrared (IR) de-excitation is reporte...

    F. Boulitrop, J. Dijon, D. J. Dunstan… in Proceedings of the 17th International Conf… (1985)