abstract
La9.33Si2Ge4O26 materials have been fabricated from La2O3, SiO2 and GeO2 powders by high speed mechanical alloying followed by conventional and microwave hybrid sintering at different temperatures and holding times. XRD data showed that the apatite phase is formed after 1 h of mechanical alloying at 850 rpm. This phase remained stable after conventional sintering in an electric furnace with density increasing as sintering temperatures and holding times were increased. However, the highest density was achieved for samples sintered in the microwave furnace (5.44 g cm(-3)), corresponding to a relative density of 98%. The electrical conductivity of the samples microwave sintered at 700 and 800 degrees C are 4.72x10(-3) and 1.93x10(-2) S.cm(-1), respectively, with a correspondent activation energy of 0.952 eV.
keywords
DOPED LANTHANUM SILICATE; APATITE-TYPE; DEFECT CHEMISTRY; ELECTROLYTES; CONDUCTIVITY; MICROSTRUCTURE; SOFC; GERMANATES; ROUTE; BULK
subject category
Materials Science
authors
Vitorino, N; Oliveira, FAC; Marcelo, T; Abrantes, JCC; Trindade, B
our authors
João Carlos de Castro Abrantes
Professor Adjunto
Nuno Miguel Dias Vitorino
Post-doc Fellowshipacknowledgements
This work was developed within the scope of the projects CEMUC - Centro de Engenharia Mecanica (FCT Ref. UID/EMS/00285/2013) and CICECO-Aveiro Institute of Materials, POCI-01-0145-FEDER-007679 (FCT Ref. UID/CTM/50011/2013 and grant SFRH/BPD/99367/2013), financed by national funds through the FCT/MEC and when appropriate co-financed by FEDER under the PT2020 Partnership Agreement.; SEM and XRD facilities were funded by FEDER Funds through QREN - Aviso SAIECT-IEC/2/2010, Operacao NORTE-07-0162-FEDER-000050.