Open AccessTHE PECULIARITIES OF THERMO-INDUCED KINETICS IN THICK FILMS OF SPINEL-TYPE CERAMICS
Author(s) -
V. Balitska
Publication year - 2019
Publication title -
vìsnik lʹvìvsʹkogo deržavnogo unìversitetu bezpeki žittêdìâlʹnostì
Language(s) - English
Resource type - Journals
eISSN - 2708-1389
pISSN - 2078-4643
DOI - 10.32447/20784643.19.2019.01
Subject(s) - ceramic , materials science , spinel , thermodynamics , isothermal process , relaxation (psychology) , kinetics , degradation (telecommunications) , thermal conduction , thermal shock , electrical resistance and conductance , analytical chemistry (journal) , composite material , chemistry , metallurgy , computer science , physics , telecommunications , psychology , social psychology , chromatography , quantum mechanics
. Today the problem of stabilization of exploitation parameters of functional elements of electron tech-nique become very actually. In this reason in modern radio-electronic equipment the functional elements based on thick films technology with high structure compactness and enough stability to environmental influences are widely used. Purpose. The aim of this work is establishment kinetics of thermoinduced degradation in thick films of spinel-type ceramics based on mixed transition-metal oxymanganites. Methods. The degradation tests were carried out in the long-term isothermal exposure of samples (356 hours) at the 170C in the heat camera HPS 222. Electrical resistances of ceramics samples were measured using digital multime-ter В7-27А/1. The measurements of nominal resistance R were carried out at 25C after certain hours of corresponding stages of thermoexposure during 64, 104, 144, 198, 251, 304 and 356 hours. The relative resistance drift ΔR/R0 (R0 – initial resistance, ΔR – change of electrical resistance caused by degradation test) was used as controlled parameter. The control of temperature was carried out by thermometer ТО-ЦО24. With a purpose of adequate mathematical description of the observed degradation kinetics, the numerical values of different fitting parameters in corresponding relaxation functions were calculated in such a way to minimize the mean-square deviation err of the experimentally measured points from the chosen relaxation function. Results. As a result of experimental study of thermoexposure the effect of thermal shock at the 170оC was re-vealed in Cu0,8Ni0,1Co0,2Mn1,9O4 and Cu0,1Ni0,8Co0,2Mn1,9O4 and sample, while in Co-enriched samples the effect of smooth decrease of electrical resistance was observed.Conclusion. The kinetics of thermodegradation of electrical resistance at 170оC in Cu0,1Ni0,8Co0,2Mn1,9O4 and Cu0,8Ni0,1Co0,2Mn1,9O4 samples were caused by homogeneity structure of sample, while in the Co-enriched compo-sition – contribution of thermoinduced diffusive processes of contacts materials as well as burning of organic binding.