Magnetic iron oxides from a tuffite from Alto Paranaíba, state of Minas Gerais, Brazil

Química Nova

Centro Universitário de Patos de Minas, Patos de Minas¹  Universidade Federal de Minas Gerais, Belo Horizonte¹  Universidade Federal de Viçosa, Viçosa¹  Couceiro, Paulo Rogério da Costa¹  Goulart, Antonio Taranto¹  Ker, João Carlos¹  Silva, Fernando Dias da¹  Fabris, José Domingos¹ 

关键词: magnesioferrite;    Rietveld;    Mö;    ssbauer.;   

DOI  :  10.1590/S0100-40422005000100002

学科分类：化学（综合）

来源: Sociedade Brasileira de Quimica

【 摘 要 】

The Mössbauer analysis along with the structural Rietveld refinement based on powder X-ray data for the magnetic fraction (saturation magnetization, s = 19 J T-1 kg-1) separated from a tuffite material from Alto Paranaíba, state of Minas Gerais, Brazil, reveal that a (Ti, Mg)-rich maghemite (deduced s = 17 J T-1 kg-1) and, for the first time observed in this lithodomain, magnesioferrite (characteristic s = 21 J T-1 kg-1) respond for the magnetization of the rock material. Consistent models for the ionic distribution in these iron-rich spinel structures are proposed.

【 授权许可】

Unknown