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

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• 作者：Man-Rong Li ; Peter W. Stephens ; Maria Retuerto ; Tapati Sarkar ; Christoph P. Grams ; Joachim Hemberger ; Mark C. Croft ; David Walker ; Martha Greenblatt
• 刊名：Journal of the American Chemical Society
• 出版年：2014
• 出版时间：June 18, 2014
• 年：2014
• 卷：136
• 期：24
• 页码：8508-8511
• 全文大小：324K
• 年卷期：v.136,no.24(June 18, 2014)
• ISSN：1520-5126

文摘

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鈥睴₆ family with unusually small cations at the A-site and a d⁰ electron configuration ion at B鈥?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 (P_S) of 50 渭C/cm² along the c-axis was obtained from point charge model calculations. Zn₂Fe³⁺Ta⁵⁺O₆ has a lower magnetic transition temperature (T_N 22 K) than the Mn₂FeTaO₆ analogue but is less conductive. The dielectric and polarization measurements indicate a potentially switchable component.