Rapidly synthesized dense BaTa(O,N)_(3)ceramics with high permittivityOA
Over the past twenty years,there has been high demand for novel functional materials for use in high-capacity dielectrics.Perovskite-type oxynitrides,which are derived from the introduction of nitrogen atoms into their corresponding oxides,possess a variety of improved chemical and physical properties.The dielectric performance of BaTa(O,N)3 is highly dependent on its purity,density,and microstructure.However,conventional sintering methods often result in low-density samples(<90%theoretical density)with many impurities,leading to poor dielectric properties.In this study,we adopted a two-step sintering method,i.e.,rapid spark plasma sintering at a lower temperature followed by postannealing in flowing ammonia at a higher temperature,to obtain BaTa(O,N)3 ceramic bulks with both high density and purity(up to 96.7%theoretical density and 97.94 wt%oxynitride phase content).The average particle size is 281.1 nm,with a uniform distribution of all the elements.The measured dielectric constant is as high as 2.1×10^(5)at 100 Hz(room temperature),which surpasses the values reported for other oxynitride dielectrics.A notable and unusual dielectric enhancement was observed at elevated temperatures,with the value reaching~10^(7)at 200−250℃.This mechanism can be attributed to defect-mediated polarization,including anion-ordering-induced permanent dipoles and oxygen vacancies,and thermally activated reconfigurable polar nanoregions that are verified by calculation and in situ transmission electron microscopy(TEM)analysis.These findings establish a general pathway to fabricate dense oxynitride ceramic bulks with high purity and collective permittivity for prospective applications in high-performance dielectric devices.
Duan Li;Sirui Ran;Jiangshan Peng;Lei Zeng;Zhiyi Yang;Songhe Yang;Yanfei Wang;Rongjun Liu
Science and Technology on Advanced Ceramic Fibers and Composites Laboratory,College of Aerospace Science and Engineering,National University of Defense Technology,Changsha 410073,ChinaScience and Technology on Advanced Ceramic Fibers and Composites Laboratory,College of Aerospace Science and Engineering,National University of Defense Technology,Changsha 410073,ChinaScience and Technology on Advanced Ceramic Fibers and Composites Laboratory,College of Aerospace Science and Engineering,National University of Defense Technology,Changsha 410073,ChinaScience and Technology on Advanced Ceramic Fibers and Composites Laboratory,College of Aerospace Science and Engineering,National University of Defense Technology,Changsha 410073,ChinaScience and Technology on Advanced Ceramic Fibers and Composites Laboratory,College of Aerospace Science and Engineering,National University of Defense Technology,Changsha 410073,ChinaKey Laboratory of Interfacial Science and Engineering of Materials(SKLISEM),School of Environmental Science and Engineering,Southern University of Science and Technology,Shenzhen 518055,ChinaScience and Technology on Advanced Ceramic Fibers and Composites Laboratory,College of Aerospace Science and Engineering,National University of Defense Technology,Changsha 410073,ChinaScience and Technology on Advanced Ceramic Fibers and Composites Laboratory,College of Aerospace Science and Engineering,National University of Defense Technology,Changsha 410073,China
化学化工
oxynitridespark plasma sintering(SPS)densificationin situ transmission electron microscopypermittivity
《Journal of Advanced Ceramics》 2026 (2)
P.25-35,11
supported by the Science and Technology Innovation Program of Hunan Province(Grant No.2023RC3024)the National Natural Science Foundation of China(Grant No.51702361).
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