Synthesis of Co_xMn_1−xO₄ (0.9x2.7) nanopowders with controlled phase and composition via a gel-combustion method

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• 作者：HyukSu Han^a ; Jae Seok Lee^b ; Jiun Lim^c ; Kyoung Ryeol Park^d ; Kang Min Kim^a ; Jeong Ho Ryu^e ; Sunghwan Yeo^f ; Jennifer Forrester^g ; Sungwook Mhin^d ; ^{hyeleci@kitech.re.kr" class="auth_mail" title="E-mail the corresponding author}
• 关键词：Co&ndash ; Mn&ndash ; O ; Gel combustion ; Nanopowders ; Thermistor
• 刊名：Ceramics International
• 出版年：2016
• 出版时间：15 November 2016
• 年：2016
• 卷：42
• 期：15
• 页码：17168-17173
• 全文大小：2167 K

文摘

Co_xMn_3−xO₄ (CMO) nanopowders with a wide compositional range (0.9≤$\le$x≤$\le$2.7) are synthesized using a gel combustion method. The effect of Co content and calcination temperature on the crystal structure of the CMO nanopowders is studied using X-ray diffraction. A highly crystalline cubic spinel structure can be obtained at a relatively low temperature (~700 °C) for CMO with a Co content of 1.8. Further increases in Co content to 2.7 leads to a higher formation temperature (~800 °C) required in order to form a crystalline cubic structure. X-ray photoelectron spectroscopy revealed that the Co and Mn cations have mixed valence states. Energy dispersive X-ray elemental mapping indicates that Co and Mn cations are homogeneously distributed in the CMO nanopowders. Thermogravimetric analysis, Fourier transform infrared, scanning electron microscopy, and X-ray fluorescence are utilized to investigate the formation of the CMO nanopowders, as well as the compositional and structural properties.