Characterization of Ternary Compounds in the BaO:Fe2O3:TiO2System: Ba6Fe45Ti17O106and BaFe11Ti3O23

✍ Scribed by T.A. Vanderah; W. Wong-Ng; B.H. Toby; V.M. Browning; R.D. Shull; R.G. Geyer; R.S. Roth

• Publisher: Elsevier Science
• Year: 1999
• Tongue: English
• Weight: 548 KB
• Volume: 143
• Category: Article
• ISSN: 0022-4596
• DOI: 10.1006/jssc.1999.8075

✦ Synopsis

Single crystals of Ba 6 Fe 45 Ti 17 O 106 and BaFe 11 Ti 3 O 23 were obtained as major and minor coproducts, respectively, by slowcooling an off-stoichiometric BaO:Fe 2 O 3 :TiO 2 melt. The former compound exhibits variable stoichiometry, Ba 6 Fe 48؊x Ti 14؉x O 106 , with the Fe:Ti ratio dependent upon the partial pressure of oxygen. The value of x corresponds to the equivalents of reduction that occur to maintain electroneutrality as the Ti-content increases. When prepared in air, this phase occurs at x ‫؍‬ 3 with the stoichiometry Ba 6 Fe 45 Ti 17 O 106 , while in 100% oxygen the x-value approaches zero with the resulting stoichiometry Ba 6 Fe 48 Ti 14 O 106 (all Fe 3؉ and Ti 4؉ ). The structures of Ba 6 Fe 45 Ti 17 O 106 and BaFe 11 Ti 3 O 23 were solved using single-crystal X-ray diffraction methods. Ba 6 Fe 45 Ti 17 O 106 was prepared in polycrystalline form, and further structural details, including accurate Fe/Ti occupancy factors, were determined by a combined refinement using neutron and synchrotron powder diffraction data. (Ba 6 Fe 45 Ti 17 O 106 : Space group C2/m (No. 12);