Crystallization and microstructure of glasses in the system Na{sub 2}O/MnO/SiO{sub 2}/Fe{sub 2}O{sub 3}

Journal Article · Sat Jan 15 00:00:00 EST 2011 · Materials Research Bulletin

DOI:https://doi.org/10.1016/J.MATERRESBULL.2010.09.036· OSTI ID:22209979

Harizanova, Ruzha ^[1]; Voelksch, Guenter; Ruessel, Christian ^[2]

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1. Physics Dept., University of Chemical Technology and Metallurgy, 8 Kl. Ohridski Blvd., 1756 Sofia (Bulgaria)
2. Otto-Schott-Institut, Universitaet Jena, Fraunhoferstr. 6, 07743 Jena (Germany)

Glasses with the compositions (100 - x)(0.16Na{sub 2}O/0.10MnO/0.74SiO{sub 2})/xFe{sub 2}O{sub 3}, (x = 5-30) and 16Na{sub 2}O/10MnO/(74 - y)SiO{sub 2}/yFe{sub 2}O{sub 3} (y = 5-30) were studied using X-ray diffraction and scanning electron microscopy. The effect of the chemical composition and the thermal history on the phase formation and the resulting microstructure was investigated. During cooling, the precipitation of ferrimagnetic solid solutions Fe{sub 3}O{sub 4}/Mn{sub 3}O{sub 4} was observed. These crystals show dendritic or platelet shape, whereby the platelets are ferromagnetic and the dendrites - mainly paramagnetic. The tendency towards crystallization can be suppressed by increasing the Na{sub 2}O-concentration. In contrast to glasses without manganese oxide, the precipitation of hematite is not observed. Therefore, the addition of reducing agents is not required, in order to crystallize large volume concentrations of the ferrimagnetic phase.

• OSTI ID: 22209979
• Journal Information: Materials Research Bulletin, Vol. 46, Issue 1; Other Information: Copyright (c) 2010 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA); ISSN 0025-5408
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ATOMIC FORCE MICROSCOPY
CHEMICAL COMPOSITION
CRYSTALLIZATION
DENDRITES
FERRITES
GLASS
HEMATITE
IRON OXIDES
MAGNETIC PROPERTIES
MANGANESE OXIDES
MICROSTRUCTURE
PRECIPITATION
REDUCING AGENTS
SCANNING ELECTRON MICROSCOPY
SILICA
SILICON OXIDES
SODIUM OXIDES
SOLID SOLUTIONS
X-RAY DIFFRACTION