Naslov
Formation of nanacrystalline NiFe2O4

Autori
Gotić, Marijan ; Czako-Nagy, Ilona ; Popović, Stanko ; Musić, Svetozar

Izvornik
Philosophical magazine letters (0950-0839) 78 (1998), 3; 193-201

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
Nickel ferrite. Mossbauer. Magnetite. Particles. Hematite. Powders

Sažetak
Coprecipitates, Ni(OH)2+2Fe(OH)3 , were milled in a planetary mill, using an agate bowl and balls (99.9% SiO2), and then heated at a maximum temperature of 573 or 773 K. The Mössbauer spectra at 298 K of the ball-milled samples (not heated) showed the superposition of two quadrupole doublets. After heating at 573 K, the superposition of two doublets was preserved at 298 K with a slight increase in the quadrupole splitting for the sample ball-milled for 64 h. After heating at 573 K, the ball-milled samples showed at 80 K a central quadrupole doublet and a sextet with very broad lines. All the samples heated to 573 K were amorphous for XRD, while those heated to 773 K exhibited crystalline NiFe2O4 with broadened diffraction lines. At 298 K, the superposition of two sextets in the Mössbauer spectra was observed for the samples obtained after heating at 773 K, indicating the presence of nickel ferrite as a single phase. The average sizes of NiFe2O4 crystallites were in nanosize range (8 to 12 nm). The FT-IR spectra of the samples heated at 773 K showed two very strong bands with positions at 601 to 603 and 408 to 411 cm-1, which can be ascribed to NiFe2O4.

Izvorni jezik
Engleski

Znanstvena područja
Kemija

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