Phase relations have been investigated within the Sr5Nb4O15−SrTiO3−Sr4Nb2O9 region of the SrO−Nb2O5−TiO2 system with a view to clarifying the occurrence of fully oxidised perovskite related phases. Overall phase analysis was carried out by powder X-ray diffraction and microstructures were clarified by transmission electron microscopy. There is only one main composition triangle in this area at 1350°C. The tie-line between Sr5Nb4O15 and SrTiO3 contains a homologous series of hexagonal layered perovskite phases including Sr6Nb4TiO18 and Sr7Nb4Ti2O21. The phase Sr4Nb2O9 is a nonstoichiometric phase with a disordered perovskite structure. There is some extension of this phase along the Sr4Nb2O9−SrTiO3 tie-line, but SrTiO3 does not show a significant composition range. Samples with a composition Sr4Nb2O9, when heated at 900°C show several ordered modifications. Samples along the Sr4Nb2O9−SrTiO3 tie-line which are annealed at 900°C contain these ordered materials together with samples showing considerable short range order which increases as the Ti content increases.
Research on Chemical Intermediates – Springer Journals
Published: Apr 15, 2009
It’s your single place to instantly
discover and read the research
that matters to you.
Enjoy affordable access to
over 18 million articles from more than
15,000 peer-reviewed journals.
All for just $49/month
Query the DeepDyve database, plus search all of PubMed and Google Scholar seamlessly
Save any article or search result from DeepDyve, PubMed, and Google Scholar... all in one place.
All the latest content is available, no embargo periods.
“Whoa! It’s like Spotify but for academic articles.”@Phil_Robichaud