Universitiy of Potsdam

Applied Condensed Matter Physics

Prof. Dr. Reimund Gerhard
2016-11-04 16:30 by Manuel Schulze

How does the PPS method work?


Schematic set-up of the PPS method after Eisenmenger (W. Eisenmenger and M. Haardt Solid State Comm., Vol. 41, pp. 917-920, 1982)

  1. A piezoelectric quartz plate (3mm thick) is driven by a 100 ns long square voltage pulse (400 V amplitude).
  2. A 200 nm thin silicone-oil layer is used to couple the resulting pressure step into the sample.
  3. The sample response is detected between a conducting-rubber electrode on the upper sample surface and the grounded quartz metallization and is fed into a very fast pre-amplifier (1 GHz bandwith), the output of which is connected to a Tektronix TDS 784 A digital storage oscilloscope

The propagation of the step wave through a sample leads to a compression of the sample volume which necessitates a temporary rearrangement of the induction charges on the electrodes which manifests itself as a current between the electrodes.

See next page for typical oscilloscope traces.