Excess noise and its temperature dependence in thick-film (cermet) resistors

Measurements have been made of the current noise in thick-film resistors (TFR) based on Ru-pyrochlore conductive grains, with sheet resistivities covering a range of four decades. The temperature dependence of the exponent alpha in the 1/f^alpha noise spectra and of the relative integral noise was investigated in the temperature range from 77 to 650K. It is shown that the presence of a minimum in the relative voltage noise fluctuations ( Delta V²)/(V)² is a general phenomenon, as is the increase in alpha with increasing temperature. Nevertheless these two effects seem not to be mutually correlated. The possibility of developing an interpretive model for noise phenomena in TFR is discussed.