In order to reduce the resistivity drift under thermal stress(ageing) of negative temperature coefficient (NTC) thermistors, largebaryum cations are added to nickel manganites Ni_xMn_3-xO_4 ( the baeof industrial thermistors). The structure of the oxides is correlatedto the Electrical properties. The additionnal hollandite BaMn_8O_16phase is responsible for a significant Decrease of the resistivity.By varying the amount of baryum initially introduced during theSynthesis, the resistivity can be modulated in a wide range (12000 Ω.cm for 0/100 at. Ba).
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