Quest for Lead Free Relaxors in YIn1鈥?i>xFexO3 (0.0 鈮?x 鈮?1.0) System: Role of Synthesis and Structure

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• 作者：Rakesh Shukla ; Farheen N. Sayed ; Vinita Grover ; Sudhanshu K. Deshpande ; Apurav Guleria ; Avesh K. Tyagi
• 刊名：Inorganic Chemistry
• 出版年：2014
• 出版时间：October 6, 2014
• 年：2014
• 卷：53
• 期：19
• 页码：10101-10111
• 全文大小：705K
• ISSN：1520-510X

文摘

The B-site tailored YIn_1鈥?i>xFe_xO₃ (0.0鈮?x鈮?1.0) series was synthesized by glycine-aided gel-combustion technique and subjected to extensive structural and electrical investigations. The temperature had tremendous bearing on the phase evolution exhibited by the system. The entire system crystallized as C-type metastable polymorph in the as鈥搒ynthesized form. Hexagonal polymorphs of Fe³⁺-rich compositions could be isolated by controlled heat treatment at 750 掳C. Raman spectroscopic investigations showed that, while there is a general shrinkage of the lattice due to substitution of a smaller ion at In³⁺-site, there is an apparent dilation of the Y鈥揙 bond, and this anomaly reflects in the electrical behavior exhibited by the system. The single-phasic hexagonal nominal compositions, YIn_1鈥?i>xFe_xO₃ (0.0 鈮?x 鈮?0.3), were also studied by impedance spectroscopy. The dielectric constant was found to drastically increase from 10 for YInO₃ to 1000 for YIn_0.7Fe_0.3O₃ at room temperature stressing the role of B-site tailoring on electrical behavior. More interestingly, careful substitution of Fe into YInO₃ could tune the electrical behavior from a dielectric to relaxor ferroelectric in the temperature range studied. The nominal composition YIn_0.7Fe_0.3O₃ showed a classical relaxor ferroelectric like behavior which is an important observation in context of the search for new lead free relaxor materials.