中国科学院无机功能材料与器件重点实验室 

Synthesis, electric and magnetic properties of Cu-doped sodium cobaltite ceramics 

　　Prof. Goran Brankovic 

　　Institute for Multidisciplinary Research,  

　　University of Belgrade, Serbia 

　　时间：2016年05月13日（星期五）下午14:00 

　　地点： 4 号楼 14楼第一会议室 

　　联系人：郑嘹赢  研究员 

　　         李国荣　研究员 

　　欢迎各位老师同学光临! 

　　CV- Goran Brankovic 

　　Goran Brankovic is a Research Professor and Head of Materials Science Department at the Institute for Multidisciplinary Research-University of Belgrade.  

　　He earned B.Sc. in Physics (University of Belgrade, 1993), M.Sc. in Materials Science (University of Belgrade, 1999) and Ph.D. in 2002 at Institute of Chemistry–UNESP, Brazil in field of Physical Chemistry. He received two grants for postdoctoral research: 2002-2003 (UFSCar, Sao Carlos, Brasil), 2007 (Institut Jozef Stefan, Ljubljana, Slovenia). Dr. Brankovic was Visiting Scientist at Instituto de Qiumica-UNESP, SP, Brazil (2011) and at Texas A&M University (2014). Goran Brankovic was Lecturer on courses "Materials in electronics" and " Structure of Materials" at Multidisciplinary Graduate School of University of Belgrade, Materials Science Program (2003-2008). He was leader of 5 national and international projects. Currently he is leader of the project titled "Zero–to Three-Dimensional Nanostructures for Application in Electronics and Renewable Energy Sources: Synthesis, Characterization and Processing" (2011-2016), financed by Ministry of Science of Republic of Serbia. He is author of 99 articles published in international peer-reviewed journals. His research interests are solid state physics, synthesis and characterization of the new materials, especially electroceramics and nanostructured materials. He is member of The Serbian Chemical Society, Serbian Microscopy Society, The Serbian Ceramic Society and The European Ceramic Society. 

　　Abstract 

　　Layered sodium cobaltite ceramics is multifunctional material with interesting electric and magnetic properties. In this work, polycrystalline samples of NaCo_2-xCu_xO₄ (x = 0, 0.01, 0.03, 0.05, 0.1) were prepared using two methods: mechanochemically assisted solid-state reaction method (SSR) and citric acid complex method (CAC). Bulk samples were prepared by pressing into disc-shaped pellets and subsequently subjected to a thermal treatment at 880 °C in inert argon atmosphere. Changes in structural and microstructural characteristics of the samples, caused by substitution of Cu for Co, were characterized using X-ray powder diffraction analysis, and scanning electron microscopy, respectively. The results of ICP analysis showed that the compositions of the samples in the final products were very close to the nominal compositions. The magnetic susceptibility of SSR sample showed an antiferromagnetic transition at T_N= 30 K, pointing to the presence of undesirable phase of Co₃O₄, which wasn’t detected by XRD, while the magnetic susceptibility of CAC sample did not show any transition in an observed temperature interval. From the results obtained in this study, observed changes in microstructure samples were correlated with changes in the lattice parameters, emphasizing the influence of Cu ion incorporation in Na_xCo₂O₄ crystal lattice.