Comparison of Linearized Electrical Degradation Kinetics in Metal-Activated Spinel (Cu,Ni,Co,Mn)3O4 Ceramics-Matrix Nanocomposites

Phenomenological models of degradation kinetics are considered for jammed systems like inhomogeneous ceramics-matrix nanocomposites, which are exemplified, in part, by screen-printed Cu0.1Ni0.1Co1.6Mn1.2O4spinel ceramics with conductive Ag and Ag-Pd contacting alloys.Structurally-intrinsic inhomogeneities due to Ag or Ag-Pd diffusants in spinel ceramics environment are shown to define governing kinetics of thermally-induced electrical degradation at 170 • C, obeying an obvious non-exponential behaviour in negative relative resistance drift.Numerical parametrization of this phenomenon (in part, determination of kinetics-responsible scaling exponent β) can be simply performed within indirect linear least-square analysis applied to generalized relaxation function presented in the double-logarithmic plot of variables.Crossover from stretched-exponential (0 < β < 1) to compressed-exponential (β > 1) degradation kinetics is revealed in these nanocomposites depending on the contacting diffusants, i.e., conductive Ag-Pd (β = 0.58) or Ag (β = 1.68) compounds.