Structural Studies of CaAl12O19, SrAl12O19, La2/3+δAld12-δO19, and CaAl10NiTiO19 with the Hibonite Structure; Indications of an Unusual Type of Ferroelectric

Published

March 1, 2016

Author(s)

Jun Li, Elena A. Medina, Judith K. Stalick, Arthur W. Sleight, M. A. Subramanian

Abstract

Various oxides with the hibonite structure were synthesized and structurally analyzed using powder neutron diffraction. The structure of CaAl₁₂O₁₉ at 298 K and 11 K shows dipoles that are apparently too dilute to order unless subjected to a suitable electric field. Magnetoplumbites, such as BaFe₁₂O₁₉, are isostructural with hibonite. These compounds possess ferromagnetic properties, which combined with the electric dipoles may influence multiferroic behavior. Our SrAl₁₂O₁₉ sample showed two distinct hexagonal phases, a major phase with the normal hibonite structure and a minor phase having a closely related structure. Our sample of the defect hibonite La_2/3+δAld12-δO₁₉ phase shows a distinctly higher δ value (0.25) vs that reported (0.15) for samples made from the melt. Finally, we used to advantage the negative scattering length of Ti to determine the site occupancies of Ni Nd Ti in CaAl₁₀NiTiO₁₉.

Citation

Zeitschrift Fur Naturforschung Section B-A Journal of Chemical Sciences

Volume

71

Issue

5

Pub Type

Journals

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Keywords

hibonite, ferroelectricity

Citation

Li, J. , Medina, E. , Stalick, J. , Sleight, A. and Subramanian, M. (2016), Structural Studies of CaAl₁₂O₁₉, SrAl₁₂O₁₉, La_2/3+δAld12-δO₁₉, and CaAl₁₀NiTiO₁₉ with the Hibonite Structure; Indications of an Unusual Type of Ferroelectric, Zeitschrift Fur Naturforschung Section B-A Journal of Chemical Sciences, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=920123 (Accessed April 19, 2024)