Effects of Substitutions of Titanium(IV) Ions by Iron(III) and Niobium(V) Ions on Phase Formation in Lanthanide-Containing Systems Comprising Layered Bismuth Titanate Ferrite

• Published in: Russian journal of inorganic chemistry Vol. 65; no. 11; pp. 1654 - 1661
• Main Authors: Mitrofanova, A. V., Fortal’nova, E. A., Safronenko, M. G., Politova, E. D., Mosunov, A. V., Venskovskii, N. U.
• Format: Journal Article
• Language: English
• Published: Moscow Pleiades Publishing 01.11.2020
• Subjects: Chemistry; Chemistry and Materials Science; Inorganic Chemistry; Synthesis and Properties of Inorganic Compounds; phase transitions; phase formation; Aurivillius phase; pyrochlore structure; layered perovskite
• ISSN: 0036-0236; 1531-8613
• DOI: 10.1134/S0036023620110133

Phase formation in the series of Bi 3 Nd 2 Fe 1 +   y Ti 3 – 2 y Nb y O 15 and Bi 3 Tb 2 Fe 1 +   y Ti 3 – 2 y Nb y O 15 ( y = 0.0–0.6 and Δ y = 0.2) samples is studied. When Bi 3 Nd 2 Fe 1 +   y Ti 3 – 2 y Nb y O 15 solid solutions (ss) are doped with niobium(V) ions, the formation of Bi 3 Nd 2 FeTi 3 O 15 layered perovskite, a member of the Aurivillius phase family of general formula A m   – 1 Bi 2 B m O 3 m   + 3 ( m = 4), is not dominant in samples where y ≥ 0.2. Bi 4 Ti 3 O 12 ( m  = 3) and NdFeO 3 phases are formed in the course of phase interaction under the chosen conditions. With higher niobium(V) amounts, a Bi 2 Ti 2 O 7 -base pyrochlore ss phase is formed in the Bi 3 Tb 2 Fe 1 +   y Ti 3 – 2 y Nb y O 15 multicomponent system. Dielectric spectroscopy shows that the phases in samples of both series where y > 0.0 undergo structural alterations associated with magnetic and electric ordering.