1/f Noise in Metal Contacts and Granular Resistors

To measure the current noise in metal contacts and granular resistors, we arranged a noise measuring system with a switched-capacitor filter. The samples are crossbar contacts and grphite thick-film resistors. All noise spectra are the 1/f type. The noise of crossbar contacts and thick-film resistors increases in proportion to the fifth and third power of the resistance, respectively. A model for the noise of metal contacts and granular resistors is proposed. It is based on the spontaneous fluctuation of temperature of the small Conducting spots between metal surfaces and granular boundaries, respectively. The results of the analysis are qualitatively in agreement with those of measurement.