Cermet resistors based on ruthenium dioxide and in some instances iridium dioxide have been found to have unusually low Temperature Coefficients of Resistivity (TCR) when a particular glass frit and a vanadium oxide additive are utilized. These unique resistors exhibit TCR's of less than .+-.25 ppm/.degree....http://www.google.com.au/patents/US4006278?utm_source=gb-gplus-sharePatent US4006278 - Low temperature coefficient of resistivity cermet resistors
