Hydrogen-Induced Failure in ZnO Multilayer Ceramic Chip Varistors with a Zinc Phosphate Passivation Layer
Zinc oxide multilayer ceramic chip varistors (MLVs) with a zinc phosphate passivation layer were studied using electrochemical hydrogen charging, in which hydrogen was deposited on the termination electrodes of MLVs through the electrolysis of water in 0.01m NaOH solution. The properties of the MLVs remained stable during the first stage of electrochemical hydrogen charging, except that the capacitance was increased slightly. Then a second stage appeared in which the properties of the MLVs were quickly and greatly degraded. The zinc phosphate passivation layer was found to be responsible for producing the first stable stage of electrochemical hydrogen charging. A passivation layer is of great importance to prevent hydrogen-induced failure for MLVs in service.
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Document Type: Research Article
Department of Physics and Key Laboratory of Acoustic and Photonic Materials and Devices of Ministry of Education, Wuhan University, Wuhan 430072, China
Department of Applied Physics and Materials Research Centre, The Hong Kong Polytechnic University, Hong Kong, China
Shenzhen CSG Electronics Co. Ltd., ShenZhen 518057, China
Publication date: 2008-06-01