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	Provedor de dados Rev. Bras. Ciênc. Solo (2) Ciência Rural (1) Autor Batista,Marcelo Augusto (1) Bigham,Jerry Marshal (1) Carducci,Michael D. (1) Chaves,Lucia Helena Garófalo (1) Chorover,Jon (1) Costa,Antonio Carlos Saraiva da (1) Curry,Joan Elizabeth (1) Fink,Jessé Rodrigo (1) Inda,Alberto Vasconcellos (1) Santos,Tatiele Fruett dos (1) Souza Junior,Ivan Granemann de (1) Stone,David Andrew (1) Mais... Palavra-chave X ray diffraction (3) Goethite. (1) Hematite (1) Iron oxides (1) Isomorphic substitution (1) Isomorphous substitution (1) LDH (1) Layered double hydroxide (1) Mass-specific magnetic susceptibility (1) Mineralogy (1) Specific surface area (1) Mais... Tipo do documento Info:eu-repo/semantics/article (3) Ano 2018 (1) 2009 (1) 2008 (1) País Brazil (3) Idioma Inglês (3)		Ordenar por:  Relevância Autor Título Ano Registros recuperados: 3 Primeira ... 1 ... Última Nickel incorporation in Fe(II, III) hydroxysulfate Green Rust: effect on crystal lattice spacing and oxidation products Rev. Bras. Ciênc. Solo Chaves,Lucia Helena Garófalo; Curry,Joan Elizabeth; Stone,David Andrew; Carducci,Michael D.; Chorover,Jon. Ni(II)-Fe(II)-Fe(III) layered double hydroxides (LDH) or Ni-containing sulfate green rust (GR2) samples were prepared from Ni(II), Fe(II) and Fe(III) sulfate salts and analyzed with X ray diffraction. Nickel is readily incorporated in the GR2 structure and forms a solid solution between GR2 and a Ni(II)-Fe(III) LDH. There is a correlation between the unit cell a-value and the fraction of Ni(II) incorporated into the Ni(II)-GR2 structure. Since there is strong evidence that the divalent/trivalent cation ratio in GR2 is fixed at 2, it is possible in principle to determine the extent of divalent cation substitution for Fe(II) in GR2 from the unit cell a-value. Oxidation forms a mixture of minerals but the LDH structure is retained if at least 20 % of the... Tipo: Info:eu-repo/semantics/article Palavras-chave: Isomorphous substitution; Layered double hydroxide; LDH; X ray diffraction. Ano: 2009 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832009000500005 Cristallochemical characterization of synthetic Zn-substituted maghemites (g-Fe2-xZn xO3) Rev. Bras. Ciênc. Solo Batista,Marcelo Augusto; Costa,Antonio Carlos Saraiva da; Souza Junior,Ivan Granemann de; Bigham,Jerry Marshal. Maghemite (g-Fe2O3) is the most usually found ferrimagnetic oxide in red basalt-derived soils. The variable degrees of ionic substitution of Fe3+ for different metals (e.g. Ti4+, Al3+, Mg2+, Zn2+, and Mn2+) and non-metals in the maghemite structure influence some cristallochemical features of this iron oxide. In this study, synthetic Zn-substituted maghemites were prepared by co-precipitation in alkaline aqueous media of FeSO4.7H2O with increasing amounts of ZnSO4.7H2O to obtain the following sequence of Fe3+ for Zn2+ substitutions: 0.0, 0.025, 0.05, 0.10, 0.15, 0.20, and 0.30 mol mol-1. The objective of this work was to evaluate the cristallochemical alterations of synthetic Zn-substituted maghemites. The dark black synthetic precipitated material was... Tipo: Info:eu-repo/semantics/article Palavras-chave: Iron oxides; X ray diffraction; Mass-specific magnetic susceptibility; Specific surface area; Isomorphic substitution. Ano: 2008 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-06832008000200011 Pedogenic iron oxides in soils of the Acre State, Brazil Ciência Rural Inda,Alberto Vasconcellos; Fink,Jessé Rodrigo; Santos,Tatiele Fruett dos. ABSTRACT: Iron oxides are environmental indicators and influence on physical and chemical behavior of soils. This research aimed to identify and characterize pedogenic iron oxides in soils of the Acre state, Brazil. The soils developed from sedimentary rocks of the Solimões Formation. Twenty one samples of subsurface horizons were collected from ten soil profiles. Soil samples were analyzed by x-ray diffractometry associated to selective chemical dissolutions. Fe contents in the clay minerals (Fes), in the pedogenic iron oxides (Fed) and in the poorly crystalline oxides (Feo) were determined. The Al3+-substitution and the mean crystal diameter of goethite and hematite were estimated. Soils presented low contents of Fes and Fed. The Fed/Fes ratio indicated... Tipo: Info:eu-repo/semantics/article Palavras-chave: Mineralogy; X ray diffraction; Hematite; Goethite.. Ano: 2018 URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-84782018000800251 Registros recuperados: 3 Primeira ... 1 ... Última

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