Intense Turquoise and Green Colors in Brownmillerite-Type Oxides Based on Mn5+ in Ba2In2鈥?i>xMnxO5+x

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• 作者：Peng Jiang ; Jun Li ; A. Ozarowski ; Arthur W. Sleight ; M. A. Subramanian
• 刊名：Inorganic Chemistry
• 出版年：2013
• 出版时间：February 4, 2013
• 年：2013
• 卷：52
• 期：3
• 页码：1349-1357
• 全文大小：459K
• 年卷期：v.52,no.3(February 4, 2013)
• ISSN：1520-510X

文摘

Brownmillerite-type oxides Ba₂In_2鈥?i>xMn_xO_5+x (x = 0.1鈥?.7) have been prepared and characterized. Magnetic measurements indicate that manganese in as-prepared samples is substituting predominantly as Mnp>5+p> for all values of x with observed paramagnetic spin-only moments close to values expected for two unpaired electrons. Electron paramagnetic resonance measurements indicate that this Mnp>5+p> is present in a highly distorted tetrahedral environment. Neutron diffraction structure refinements show that Mnp>5+p> occupies tetrahedral sites for orthorhombic (x = 0.1) and tetragonal (x = 0.2) phases. For Mn 鈮?0.3 samples, neutron refinements show that the phases are cubic with disordered cations and oxygen vacancies. The colors of the phases change from light yellow (x = 0) to intense turquoise (x = 0.1) to green (x = 0.2, 0.3) or to dark green (x 鈮?0.4). Under reducing conditions, Mnp>5+p> is reduced to Mnp>3+p>, and Ba₂In_2鈥?i>xMn_xO_5+x phases become black Ba₂In_2鈥?i>xMn_xO₅ phases still with the brownmillerite structure.