Electron systems like transition metal oxides have magnetic, electric and dielectric or optical and photovoltaic properties, which are strongly correlated with each other. To analyze these properties, several stimuli have to be applied to the samples simultaneously. This was done by Matthias Hudl et al. as described in their paper “PPMS-based set up for Raman and luminescence spectroscopy at high magnetic field, high pressure and low temperature” (Hudl et al. EPJ Techniques and Instrumentation (2015) 2:3, DOI 10.1186/10.1140/epjti/s40485-015-0014-x).
The researchers from the ICT Materials Physics group of the KTH Royal Institute of Technology in Sweden successfully built a Raman and luminescence spectroscopy experiment based on a Physical Properties Measurement System (PPMS) from Quantum Design.
The Swedish system extends features of the PPMS like the large temperature range (3 - 350 K) and high magnetic field (0 - 9 T) by the ability to apply high pressures (0 - 60 GPa) and electric field strengths up to 10 MV/m. All stimuli could be applied at the same time, while measuring Raman or luminescence spectroscopy.
To set up this system they designed and fabricated a new extension for the PPMS, which was able to collect the Raman spectroscopy data:
- Custom-made Raman top part, including several imaging lenses, beam splitters, notch filters, white light illumination and a CCD camera
- Miniature nonmagnetic diamond anvil cell (DAC) sample holder
- 488 nm argon-ion CW laser system
- Shamrock spectrometer (SR-303I-A, Andor Technology Ltd.) with a thermoelectrically cooled CCD detector (iDus, Andor Technology, 1024x256 pixels, -50 °C)
- Data acquisition by the QD-PPMS third party option, which includes the Raman spectroscopy module Solis from Andor Technology Ltd. (Also available from LOT-QuantumDesign).
A schematic of the PPMS Raman set up is shown in above figure. The above mentioned paper shows measurement results for ruby, solid hydrogen and Ba3NbFe3Si2O14 at low temperatures, high hydrostatic pressure and high magnetic field.