Designing Polar and Magnetic Oxides: Zn2FeTaO6 - in Search of Multiferroics

Li, Man-Rong; Stephens, Peter W.; Retuerto, Maria; Sarkar, Tapati; Grams, Christoph P.; Hemberger, Joachim; Croft, Mark C.; Walker, David; Greenblatt, Martha

Polar oxides are technically of great interest but difficult to prepare. Our recent discoveries predicted that polar oxides can be synthesized in the corundum-derivative A2BB′O6 family with unusually small cations at the A-site and a d0 electron configuration ion at B′-site. When magnetic transition-metal ions are incorporated more interesting polar magnetic oxides can form. In this work we experimentally verified this prediction and prepared LiNbO3 (LN)-type polar magnetic Zn2FeTaO6 via high pressure and temperature synthesis. The crystal structure analysis indicates highly distorted ZnO6 and (Fe/Ta)O6 octahedra, and an estimated spontaneous polarization (PS) of ∼50 μC/cm2 along the c-axis was obtained from point charge model calculations. Zn2Fe3+Ta5+O6 has a lower magnetic transition temperature (TN ∼ 22 K) than the Mn2FeTaO6 analogue but is less conductive. The dielectric and polarization measurements indicate a potentially switchable component.


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Journal of the American Chemical Society

More About This Work

Academic Units
Lamont-Doherty Earth Observatory
American Chemical Society
Published Here
September 28, 2015