Avtor/Urednik		Čeh, M; Gu, H; Muellejans, H; Rečnik, A
Naslov		Analytical electron microscopy of planar faults in SrO-doped CaTiO3
Tip		članek
Vir		J Mater Res
Vol. in št.		Letnik 12, št. 9
Leto izdaje		1997
Obseg		str. 2438-46
Jezik		eng
Abstrakt		Oxide-rich planar faults within a perovskite matrix are the prevailing type of extended defects in polycrystalline SrO-doped CaTiO3. These defects form, depending on the temperature of sintering, random networks, or ordered structures. The chemistry of the polytypoid, the isolated planar faults, and the perovskite phase have been studied by spatialy resolved electron energy-loss and energy-dispersive x-ray spectroscopies using a dedicated scanning transmission electron microscope. We have found that Sr ions from SrO additions preferably substitute Ca in the CaTiO3 lattice, thus forming a solid solution (Ca1-xSx)TiO3 phase. Whereas the excess Ca segregates in a form of single planar faults at lower tempeatures, it forms a stable polytypoidic phase at higher temperatures. For materials having up to 25 mol % of SrO additions, this phase has (Ca1-xSrx)4Ti3O10 composition, comprising a sequence of CaO faults followed by three (Ca1-xSrx)TiO3 perovskite layers. Analytical elecron microscopy revealed that the composition of the single planar faults, formed at lower temperatures, is identical to that of polytypoids, which are stable at higher sintering temperatures.
Deskriptorji		TITANIUM CALCIUM STRONTIUM SOLUBILITY MICROSCOPY, ELECTRON, SCANNING CRYSTALLOGRAPHY, X-RAY