Mechanisms of Structural Degradation of Oxymanganospinel Ceramics for Active Elements of Temperature Sensors

The mechanisms of thermodegradation of temperature-sensitive elements on the example of two-phase Cu
0.l
Ni
0.8
Co
0.2
Mn
1.9
O
4
ceramics sintered at 1170 °C and subjected to additional heat treatment at 850 °C are considered. It is shown that the processes of additional separation of the second phase continue during thermal exposure at temperatures of 125 °C and 170 °C. The observed changes indicate the release of additional phases at the grain boundaries, which leads to an increase in the relative resistance of the ceramic. It is established that higher degradation temperature leads to more significant changes in electrical resistance. It is shown that additional temperature influences contribute to the stabilization of ceramic parameters. The degradation test at 170 °C causes a decrease in electrical resistance by 7.5
^%
, while at 125 °C the resistance drift is only 6%.