Van-der-Pauw measurement in PPMS and related instruments with an automated switchbox
Putting an ear to PPMS users we recognized, that there is a demand for 4-wired resistance measurements according to the van der Pauw method.
As shown in the schematic picture. To measure configuration A and B in one run is not possible with the standard measurement option ETO or resistivity (at multiple channels). The new switchbox ASB is exactly dedicated to enhance this measurement capability. The software controlled box (re)-routes the measurement signal by relays. So the user just loops the box into the measurement line from ETO or resistivity electronics to the sample. The box takes care of making permutation of the wires to the sample. The switching capability at a glance:
- Reverting polarity of the current leads
- Rotation of contact field by 90 degrees (as shown schematic)
- Rotation of contact field by 180 degrees
- Switching between “normal” resistance and Hall measurement
… or any combination of the above actions e.g. a rotation of 270 degrees by activating 90 and 190 degrees rotations
Contact Dr. Marc Kunzmann for more information.