Magnetoresistance of RuO/sub 2/-glass films

RuO/sub 2/-glass based materials gain the application in construction of modern temperature sensors in cryogenics. This is due to their high temperature sensitivity, remaining virtually insensitive to magnetic field. The paper addresses the question about electrical charge transport mechanism in these materials which is still open: there are many experimental studies which draw to different and sometimes contradicting conclusions. Resistance of laboratory made thick films consisting of RuO/sub 2/ and glass mixture of precisely controlling ratio have been studied in temperature range form 0.3 K to 300 K and magnetoresistance in magnetic field up to 10 T or temperatures below 4.2 K. It has been observed that at the lowest temperatures (T <) magnetoresistance changes sign from negative to positive when magnetic field increases. At higher, temperatures only positive magnetoresistance has been revealed. Data analysis involving possible conduction mechanisms (weak localization, hopping) has been performed. Conclusions are helpful in understanding physics of electron transport in RuO/sub 2/ based thick film resistors and might be useful in optimization and designing modern temperature sensors made of inhomogeneous materials.