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Synthesis of BaTiO 3 ‐20wt% CoFe 2 O 4 Nanocomposites via Spark Plasma Sintering
Author(s) -
Ghosh Dipankar,
Han Hyuksu,
Nino Juan C.,
Subhash Ghatu,
Jones Jacob L.
Publication year - 2012
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1551-2916.2012.05221.x
Subject(s) - materials science , spark plasma sintering , sintering , nanocrystalline material , crystallite , nanocomposite , spinel , composite material , barium titanate , phase (matter) , ceramic , chemical engineering , metallurgy , nanotechnology , chemistry , organic chemistry , engineering
Barium titanate‐20wt% cobalt ferrite ( BaTiO 3 ‐20wt% CoFe 2 O 4 ) nanocomposites were sintered from nanocrystalline BaTiO 3 and CoFe 2 O 4 powders using spark plasma sintering ( SPS ) and pressureless sintering ( PS ) techniques. Using SPS , dense polycrystalline composites were obtained at a sintering temperature as low as 860°C and a time of 5 min whereas PS required a higher sintering temperature (1150°C) and time (120 min) to obtain similarly dense composites. Microstructural analysis of the composites showed that both the techniques retained nanocrystalline grain sizes after sintering. High resolution X ‐ray diffraction measurements revealed that the BaTiO 3 ‐20wt% CoFe 2 O 4 composites sintered by the SPS technique did not exhibit formation of any new phase(s) due to reaction between the BaTiO 3 and CoFe 2 O 4 phases during sintering. However, the PS technique resulted in the formation of additional phases (other than the BaTiO 3 and CoFe 2 O 4 phases) in the composites. While the composites synthesized by SPS were of superior phase‐purity, evidence of Fe diffusion from the spinel to the perovskite phase was found from X‐ray diffraction and permittivity measurements.