BiFeO3-based nanoceramics prepared by spark plasma sintering

BiFeO3-based nanopowders were prepared via a sol-gel method, in which the gel (with metal-nitrate, maleic acid and water used as raw materials) was sintered at 650 degrees C for 2 hours. The aggregation of nanopowders was destroyed by high energy ball milling for 12 hours. BiFeO3-based nanoceramics were prepared by spark plasma sintering method. XRD results indicate that there are two phases, ZrO2 and BiFeO3, in the ceramics. The results of SEM observation show that the ceramic grain size is about 50 nm in diameter. These phenomena and the changes of sintering parameters indicate that ZrO2 phase exits in the grain boundaries and inhabits the growth of BiFeO3 grains. The dielectric constant of nanoceramics, about 70, is stable between 10(2) Hz and 10(6) Hz. (C) 2011 Published by Elsevier Ltd.