High-energy X-rays (HEX) above 60 keV are quite valuable, especially for partially or fully disordered materials, because they allow structural studies in both real and reciprocal space, while the moderate X-rays (e.g., 30 keV) can only be used to study the long-range periodic structure of the sample in reciprocal space [1]. The pair distribution function (PDF) technique has played an important role in characterizing the microstructure of nanoparticles in recent years [2]. In this conference, we report our recent progress in diffraction-based X-ray energy calibration [3], high-energy X-ray focusing[4] and the pressure-induced microstructural changes of nanocrystalline Au and Pt particles at high pressure [4,5].
The microstructure of nanoparticles, which is closely related to their size-dependent mechanical properties, has been intensively studied in the past decades. However, despite extensive studies, the origin of the different mechanical behaviour as a function of their particle size remains elusive due to inconsistent results. Both gold and platinum are common pressure markers in high-pressure experiments due to their low strength, moderate compressibility, chemical inertness, and good X-ray scattering power. Thus, an accurate EOS of Au and Pt is very important for high pressure research, e.g. the ultrahigh-pressure experiments in the mutli-megabar range. We will show that the internal microstructure inside nanoparticle plays a critical role in the macro-mechanical properties of n-Au and n-Pt particles.
References:
[1] T. Egami and S. J. L. Billinge, Materials Today 6, 57 (2003).
[2] S. J. L. Billinge and I. Levin, Science 316, 561 (2007).
[3] X. Hong, Z. Chen, and T. S. Duffy, Review of Scientific Instruments 83, 063901 (2012).
[4] X. Hong, L. Ehm, Z. Zhong, S. Ghose, T. S. Duffy, and D. J. Weidner, Scientific Reports 6, 21434 (2016).
[5] X. Hong, T. S. Duffy, L. Ehm, and D. J. Weidner, Journal of Physics: Condensed Matter 27, 485303 (2015).
2025-04-09 09:00:00
