{"title":"The effects of MnO2 on the microstructure and electrical properties based on ZnO-Bi2O3-Sb2O3-Cr2O3-Co2O3 varistors","authors":"Xiaolong Huang, Jiaqi Li, Guangxu Pan, Dachuan Zhu","doi":"10.1007/s10832-024-00360-2","DOIUrl":null,"url":null,"abstract":"<p>In this work, nano ZnO powders, Bi<sub>2</sub>O<sub>3</sub>, Sb<sub>2</sub>O<sub>3</sub>, Cr<sub>2</sub>O<sub>3</sub>, Co<sub>2</sub>O<sub>3</sub> and a various content of MnO<sub>2</sub> were blended thoroughly and pre-calcined at 800℃ and then pressed in to pellets which were sintered at 950℃ to form varistor ceramics. Subsequently, the effects of MnO<sub>2</sub> on the microstructure and electrical properties of the ZnO-based varistor were investigated. It was found that the amount of spinel phase (Zn<sub>7</sub>Sb<sub>2</sub>O<sub>12</sub>) and Bi<sub>2</sub>O<sub>3</sub> phase increased with the MnO<sub>2</sub> increasing, while the content of pyrochlore (Zn<sub>2</sub>Bi<sub>3</sub>Sb<sub>3</sub>O<sub>14</sub>) phase decreased. As a result, the growth of ZnO grain was reduced with the average grain size from 9.5 μm down to 5.3 μm, leading to the increase of breakdown field of ZnO-based varistor. Particularly, the ZnO-based varistor with 1.2 mol% MnO<sub>2</sub> exhibited the best comprehensive electrical performance with the breakdown field E<sub>b</sub> of 901.4 V/mm, the nonlinear coefficient α of 66.7 and the leakage current density J<sub>L</sub> of 1.1 µA/cm<sup>2</sup>.</p>","PeriodicalId":625,"journal":{"name":"Journal of Electroceramics","volume":null,"pages":null},"PeriodicalIF":1.7000,"publicationDate":"2024-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Electroceramics","FirstCategoryId":"88","ListUrlMain":"https://doi.org/10.1007/s10832-024-00360-2","RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"MATERIALS SCIENCE, CERAMICS","Score":null,"Total":0}
引用次数: 0
Abstract
In this work, nano ZnO powders, Bi2O3, Sb2O3, Cr2O3, Co2O3 and a various content of MnO2 were blended thoroughly and pre-calcined at 800℃ and then pressed in to pellets which were sintered at 950℃ to form varistor ceramics. Subsequently, the effects of MnO2 on the microstructure and electrical properties of the ZnO-based varistor were investigated. It was found that the amount of spinel phase (Zn7Sb2O12) and Bi2O3 phase increased with the MnO2 increasing, while the content of pyrochlore (Zn2Bi3Sb3O14) phase decreased. As a result, the growth of ZnO grain was reduced with the average grain size from 9.5 μm down to 5.3 μm, leading to the increase of breakdown field of ZnO-based varistor. Particularly, the ZnO-based varistor with 1.2 mol% MnO2 exhibited the best comprehensive electrical performance with the breakdown field Eb of 901.4 V/mm, the nonlinear coefficient α of 66.7 and the leakage current density JL of 1.1 µA/cm2.
期刊介绍:
While ceramics have traditionally been admired for their mechanical, chemical and thermal stability, their unique electrical, optical and magnetic properties have become of increasing importance in many key technologies including communications, energy conversion and storage, electronics and automation. Electroceramics benefit greatly from their versatility in properties including:
-insulating to metallic and fast ion conductivity
-piezo-, ferro-, and pyro-electricity
-electro- and nonlinear optical properties
-feromagnetism.
When combined with thermal, mechanical, and chemical stability, these properties often render them the materials of choice.
The Journal of Electroceramics is dedicated to providing a forum of discussion cutting across issues in electrical, optical, and magnetic ceramics. Driven by the need for miniaturization, cost, and enhanced functionality, the field of electroceramics is growing rapidly in many new directions. The Journal encourages discussions of resultant trends concerning silicon-electroceramic integration, nanotechnology, ceramic-polymer composites, grain boundary and defect engineering, etc.