High temperature induced phase transitions in SrCaCoTeO₆ and SrCaNiTeO₆ ordered double perovskites

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• 作者：A. Zaraq^a ; B. Orayech^b ; ^{borayech@cicenergigune.com" class="auth_mail" title="E-mail the corresponding author} ; ^{orayech@gmail.com" class="auth_mail" title="E-mail the corresponding author} ; A. Faik^b ; J.M. Igartua^c ; A. Jouanneaux^d ; A. El Bouari^a
• 关键词：Double perovskite ; X-ray diffraction ; Crystal structure ; Phase transitions ; Tellurium family
• 刊名：Polyhedron
• 出版年：2016
• 出版时间：28 May 2016
• 年：2016
• 卷：110
• 期：Complete
• 页码：119-124
• 全文大小：1575 K

文摘

Two new double perovskites SrCaCoTeO₆ and SrCaNiTeO₆ have been successfully synthesized via the conventional solid state reaction method. The crystal structures and phase transitions of both materials have been investigated using conventional X-ray powder diffraction method at room- and high-temperatures. The Rietveld analysis has shown that both compounds crystallize at room temperature in a primitive monoclinic perovskite-type structure with P2₁/n$P{2}_1/n$ (No. 14) space group and 1:1 ordered arrangement of the B-site cations (Co(Ni)/Te). The high temperature analysis has shown that these materials present temperature induced phase transitions following the next phase transition sequence: $P{2}_1/n(a^{-}{a}^{-}{c}^{+})\to I2/m(a^{-}{a}^{-}{c}^0)\to I4/m(a^0{a}^0{c}^{-})\to \mathit{Fm}\overline{3}m(a^0{a}^0{a}^0)$.