Bob Thurber connecting cables to the sample holder for a Hall effect measurement.
Bob Thurber connecting cables to the sample holder for a Hall effect measurement.
Contact

W. Robert Thurber
301-975-2067

100 Bureau Drive, MS 8120
Gaithersburg, MD 20899-8120
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Sources of Error

Check the following:

  1. Are the probes or wires making good contact to the sample?
  2. Are the contact I-V characteristics linear?
  3. Is any contact much higher in resistance than the others?
  4. Do the voltages reach equilibrium quickly after current reversal (there will be some delay for semi-insulating GaAs)?
  5. Is there visible damage (cracks, especially around the contacts)?
  6. Is the sample in the dark?
  7. Is the sample temperature uniform?
  8. If there are large temperature gradients across the wiring, are dissimilar wiring materials being used?