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Journal of synchrotron radiation 30(4), 671 - 685 (2023). doi:10.1107/S1600577523003910, An experimental platform for dynamic diamond anvil cell (dDAC) research hasbeen developed at the High Energy Density (HED) Instrument at the EuropeanX-ray Free Electron Laser (European XFEL). Advantage was taken of the highrepetition rate of the European XFEL (up to 4.5 MHz) to collect pulse-resolvedMHz X-ray diffraction data from samples as they are dynamically compressed atintermediate strain rates ( 10 3 s1), where up to 352 diffraction images can becollected from a single pulse train. The set-up employs piezo-driven dDACscapable of compressing samples in 340 ms, compatible with the maximumlength of the pulse train (550 ms). Results from rapid compression experimentson a wide range of sample systems with different X-ray scattering powers arepresented. A maximum compression rate of 87 TPa s1 was observed duringthe fast compression of Au, while a strain rate of 1100 s1 was achievedduring the rapid compression of N2 at 23 TPa s1., Published by Wiley-Blackwell, [Erscheinungsort nicht ermittelbar]

Half-Heusler thermoelectric materials are potential candidates for high thermoelectric efficiency. We report high-pressure thermoelectric and structural property measurements, density functional theory calculations on the half-Heusler material TiNiSn, and an increase of 15% in the relative dimensionless figure of merit, ZT, around 3 GPa. Thermal and electrical properties were measured utilizing a specialized sample cell assembly designed for the Paris-Edinburgh large-volume press to a maximum pressure of 3.5 GPa. High-pressure structural measurements performed up to 50 GPa in a diamond-anvil cell indicated the emergence of a new high-pressure phase around 20 GPa. A first-principles structure search performed using an ab initio random structure search approach identified the high-pressure phase as an orthorhombic type, in good agreement with the experimental results.