Speaker
Description
Despite the impressive developments in the
application of large volume presses at synchrotron
facilities that are catching up with the long-established
diamond anvil cell technique (DAC) for in-situ studies,
still the vast majority of multianvil high pressure
experiments (MAE) is and will be further performed at
in-house facilities without any access to in-situ
characterization based on X-ray or neutron beams. For
traditional/conventional pressure calibration in MAE, the
correllation between the pressure inside the pressure cell
and the load applied to the press needs to be established
by 'calibration' runs. With respect to pressure cell design
and gasketing, this allows only for minor deviations from
a once established 'standard assembly' without compromising
the pressure scale. The objective of our
development was to find a way of performing heated
multianvil experiments with built-in pressure calibration
for every single run. Based on previous results, we
managed to accommodate one or more fixed-point
calibrants together with a piezoresistive manganin gauge
within octahedral pressure cells of various sizes, without
interfering with the furnace assembly. The method gives
the whole compression curve and the final pressure
within the octahedron before heating. It moreover yields
important information on the unloading path of the
experiment. It does not only offer the possibility to
combine room-temperature and high-temperature
pressure calibration within a single experiment, but also
proved to be a useful tool to speed-up testing of new
multianvil assemblies and configurations.