Crystallization kinetics of Nd-substituted yttrium iron garnet prepared through sol-gel auto-combustion method

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• 作者：T. Arun ; M. Vairavel ; S. Gokul Raj¹ ; R. Justin Joseyphus ; ^{rjustinj@nitt.edu}
• 关键词：A. Sol&ndash ; gel processes ; C. Thermal properties ; Johnson&ndash ; Mehl&ndash ; Avrami model
• 刊名：Ceramics International
• 出版年：2012
• 出版时间：April 2012
• 年：2012
• 卷：38
• 期：3
• 页码：2369-2373
• 全文大小：523 K

文摘

Nd substituted Y₃Fe₅O₁₂ (YIG) was synthesized using sol-gel auto-combustion method. The phases present in the samples were identified using XRD. The asprepared dried gel was found to transform to the rare earth iron garnet phase at lower temperature when the Nd concentration is lower. Higher concentration of Nd resulted in the formation of orthoferrite as the major phase. The Curie temperature was recorded using thermomagnetic analysis and it was found to increase with the concentration of Nd. The crystallization kinetics of the Nd-substituted garnet phase was studied using TG-DTA. Two stage crystallization was observed from the DTA analysis for Nd₁Y₂Fe₅O₁₂. The activation energy for the formation of Nd₁Y₂Fe₅O₁₂ was 610 kJ/mol, found by using Johnson-Mehl-Avrami (JMA) equation. Three dimensional growth mechanism dominate at lower heating rates for the Nd-substituted YIG.