Speakers
Description
High pressure experiments are increasingly important to investigate and tune material properties of new composites and to understand their quantum behavior. For this purpose, the Paul Scherrer Institute is commissioning a new uniaxial pressure device for material research. Experiments are performed under high pressure at low temperature and high magnetic fields to test theoretical predictions of correlations between pressure, magnetism and superconductivity in different materials.
To design this new piece of equipment, we have made use of our experience of two existing devices – a piezo-system for muon spin spectroscopy [1] and a motor-driven device for neutron and X-ray scattering and combined the advantages of both approaches. This next generation device is designed to apply high uniaxial force up to 2000N for low-temperature muon experiments. The new muSR pressure device allows applying in-situ high uniaxial pressure while performing AC susceptibility measurements and muon spin spectroscopy at temperatures as low as 2K. To read data during an experiment and control the environment of the sample, strain gauges, AC susceptibility coils and temperature sensors were mounted on the device. The strain gauges are wired in a Wheatstone bridge configuration to measure strain applied to the sample.
Calibration of the sensors and motor control is done in a custom-built test-bench. The sensors provide information for feedback control software which is used to ensure that the desired pressures and temperatures are reached. The pressure device is tested with a steel sample at room temperature to ensure the correct behavior of all the components.
For a first test experiment after the setup of the pressure device, an AC susceptibility measurement of La2-xBaxCu2O4 at low temperature under compression and tension will be performed to test device’s functionality with a well-known material.
[1] Ghosh et al., Rev. Sci. Instrum. 91, 103902 (2020)
[2] Simutis et al., Rev. Sci. Instrum. 94, 013906 (2023)