Journal of Alloys and Compounds 408–412 (2006) 637–640 Preparation and conductivity measurement of Eu doped BaTiO 3 nanoceramic D. Hreniak a,∗ , W. Strek a , J. Chmielowiec b , G. Pasciak b , R. Pazik a , S. Gierlotka c , W. Lojkowski c a Institute of Low Temperature and Structure Research, Polish Academy of Sciences, ul. Okolna 2, Wroclaw, Poland b Electrotechnical Institute, Division of Electrotechnology and Materials Science, ul. M. Sklodowskiej-Curie 55/61, Wroclaw, Poland c Institute of High Pressure Physics UNIPRESS, Polish Academy of Sciences, ul. Sokolowska 29/37, Warsaw, Poland Accepted 15 December 2004 Available online 5 July 2005 Abstract The new method of fabrication of Eu 3+ :BaTiO 3 nanoceramics obtained from the sol–gel derived nanocrystalline powders is reported. It is demonstrated that under special conditions the obtained ceramics were characterized by black color. Their structural and morphology properties are described. The results of conductivity measurements are presented. The activation energy from the alternating current measurements is determined. An application of Eu 3+ :BaTiO 3 nanoceramics for the solid oxide fuel cell systems is discussed. © 2005 Elsevier B.V. All rights reserved. Keywords: Nanostructures; Sol–gel synthesis; Ionic conduction 1. Introduction It is well known that perovskite-type oxides can be used both as electrolytes and as electrodes or oxygen separa- tion membranes for solid oxide fuel cell (SOFC) [1–4]. The principal parameters, which determine a possibility of oxide materials for application as electrolytes in the efficient SOFC, are high ionic conductivity at low temperatures. Besides of that the low reactivity with contacts and chemical stability at working conditions are critical for the purposed applications. At the present time, the most promising materials demon- strate the relatively stable high ionic conductivity (close to 0.1 S/m) at the temperature below 900 ◦ C. The ferroelectric properties of BaTiO 3 nanocrystallites were recently a subject of massive investigations. The size effects on the ferroelec- tric domain creation and the formation of tetragonal structure of barium titanate were found and described in detail [5–8]. The pure and donor activated BaTiO 3 ceramics composed of ∗ Corresponding author. Present address: P. Nr. 1410, 50-950 Wroclaw 2, Poland. Tel.: +48 71 343 5021; fax: +48 71 344 1029. E-mail address: hreniak@int.pan.wroc.pl (D. Hreniak). microsized crystals were the subject of a few reports on their electrical properties and are widely used in the electronic devices as high permittivity capacitors and PTCR [9,10]. In this work, we present a novel method of fabrication of BaTiO 3 nanoceramics. It is shown that such nanoceramics may be applied as electrode materials in the SOFC systems. 2. Experimental 2.1. Samples Preparation of BaTiO 3 (BT) nanocrystals has been presented by us elsewhere [11]. Barium acetate and titanium butoxide were used as starting materials. Acetyl acetone and acetic acid were selected as solvents of titanium butoxide and barium acetate, respectively. Dissolved barium acetate was added dropwise to titanium butoxide solution with stirring. The obtained solutions were vigorously stirred at 50 ◦ C for about 2 h. The 1 mol% of europium nitrate versus barium acetate was then added. The obtained sol was heated at approximately 100 ◦ C for 24 h to form barium titanate 0925-8388/$ – see front matter © 2005 Elsevier B.V. All rights reserved. doi:10.1016/j.jallcom.2004.12.098