Estudo da oxigenação dos compostos intermetalicos Fe17r2 (R=SM, PR, ND)

AUTOR(ES)

Edival Morais

DATA DE PUBLICAÇÃO

1999

RESUMO

In this work the oxidation of the compounds Fe17R2 with R = Sm, Pr and Nd, was studied. Powder samples of the three compounds were oxidized, by gas - solid reaction, in a Sieverts type reactor, at temperatures of 225, 250, 300, 400, 500, 600, 700 and 800 oC. The treatments below 300 oC were made to study the first diffusion layer and for trying to get an eventual interstitial oxidized fase, Fe17R2Ox; similar to the nitrided fase: the oxygen concentration in the first diffusion layer for samples fully oxidized, a qualitative oxygen concentration profile in the first layer of samples partially oxidized and the diffusion patterns for different oxidizing temperatures were determined. The samples oxidized above 300 oC were destined to the identification of decomposition products of the original 17 - 2 fase by the oxygen. Nine oxides were detected, six of which were identified. The samples were characterized by optical metallography (OM), X - ray diffractiion (XRD), thermomagnetic analyses (TMA), Mössbauer spectroscopy (MS), differential thermoanalyses (DTA) and thermogravimetric analyses (TGA)

ASSUNTO(S)

propriedades magneticas materiais magneticos ligas de ferro

Documentos Relacionados

• Preparação e caracterização de monocristais das fases Fe17R2 (R=terras raras)
• Obtenção e caracterização de filmes finos ferromagneticos das fases FE17TR21 TR=Nd, Pr e Sm
• Estudo do efeito magnetocalórico nos sistemas Gd(Al1-xNix)2 e RMg2 (R=Pr, Dy, Er, Nd)
• Estudo das propriedades magneticas dos compostos R-Pnictides, R=Nd, Yb
• Nitrogenação a plasma da fase Sm2Fe17 e obtenção de imas permanentes de Sm2Fe17N3 com SN depositado quimicamente