Details

Autor(en) / Beteiligte

• Scofield, John H.

Titel

ac method for measuring low‐frequency resistance fluctuation spectra

Ist Teil von

• Review of scientific instruments, 1987-06, Vol.58 (6), p.985-993

Ort / Verlag

Woodbury, NY: American Institute of Physics

Erscheinungsjahr

1987

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• An ac technique is described for measuring low‐frequency resistance fluctuation spectra with improved sensitivity over dc methods achieved by avoiding preamplifier 1/f noise. The technique, easily implemented with decade resistors and a lock‐in amplifier, allows the current noise of low‐resistance (r<10 kΩ) specimens to be measured to frequencies below 1 mHz. Use of a center‐tapped, four‐probe specimen geometry allows discrimination between specimen and contact noise and eliminates noise due to bath temperature variations. The technique is demonstrated in use to determine the dependence of the 1/f noise of Cr films on film area. Measurements with simultaneous direct and alternating currents provide means to study the noise of nonlinear devices and frequency‐dependent conductors.