Aqueous Sol–Gel Route toward Selected Quaternary Metal Oxides with Single and Double Perovskite-Type Structure Containing Tellurium

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• 作者：Igor Djerdj ; Jasminka Popović ; Suraj Mal ; Tobias Weller ; Marko Nuskol ; Zvonko Jagličić ; Željko Skoko ; Damir Pajić ; Christian Suchomski ; Pascal Voepel ; Roland Marschall ; Bojan Kozlevčar ; Bernd M. Smarsly
• 刊名：Crystal Growth & Design
• 出版年：2016
• 出版时间：May 4, 2016
• 年：2016
• 卷：16
• 期：5
• 页码：2535-2541
• 全文大小：416K
• 年卷期：0
• ISSN：1528-7505

文摘

Highly crystalline SrFe_2/3Te_1/3O₃, Ba₃Fe₂TeO₉, and Ba₂NiTeO₆ have been synthesized by using a specially developed sol–gel route methodology, reducing the time needed employing solid-state routes and resulting in high reaction yield up to 75%. These materials have been studied by X-ray powder diffraction (XRPD), scanning and transmission electron microscopy, Raman spectroscopy, and dielectric and magnetic measurements. At room temperature, the crystal structure of SrFe_2/3Te_1/3O₃ is cubic, space group Pm3̅m, with a = 3.9373(2) Å, whereas Ba₃Fe₂TeO₉ crystallizes in the hexagonal crystal system, space group P6₃/mmc, a = 5.7691(4) Å, and c = 14.208(1) Å. The third studied perovskite Ba₂NiTeO₆ crystallizes in the trigonal R3̅m space group with a = 5.7974(4) Å and c = 28.599(2) Å. Based on structural characterization results, the obtained single and double perovskite crystallites are nearly in nanometer regime, ranging from 45 to 164 nm, building micrometer-sized particles with visible well-faceted hexagonal morphology. Magnetic measurements show the onset of ferrimagnetic ordering at relatively high temperature of 667 K for the SrFe_2/3Te_1/3O₃, whereas Ba₃Fe₂TeO₉ and Ba₂NiTeO₆ show antiferromagnetic ordering below 80 and 8.6 K, respectively. The measured room temperature dielectric constants are in the range between 15 and 77.