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

V. Balitskaa, O. Shpotyukb, c, M. Brunnerd aLviv State University of Life Safety, 35, Kleparivska Str., Lviv, 79007, Ukraine bJan Długosz University in Częstochowa, al. Armii Krajowej 13/15, 42-200 Częstochowa, Poland cVlokh Institute of Physical Optics, 23, Dragomanov Str., Lviv, 79005, Ukraine dTechnische Hochschule Köln/University of Technology, Arts, Sciences, 2, Betzdorfer Str., Köln, 50679, Germany

Received: April 2, 2019; revised version February 11, 2020; in final form February 11, 2020

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Phenomenological models of degradation kinetics are considered for jammed systems like inhomogeneous ceramics-matrix nanocomposites, which are exemplified, in part, by screen-printed Cu0.1Ni0.1Co1.6Mn1.2O4 spinel 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°, 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.

DOI:10.12693/APhysPolA.137.1027 PACS numbers: 81.05.Je