Magnetic properties of nanocrystalline NiFe2O4 powders prepared by an aqueous oxidative precipitation process
UNSPECIFIED. (2001) Magnetic properties of nanocrystalline NiFe2O4 powders prepared by an aqueous oxidative precipitation process. INTERNATIONAL JOURNAL OF MODERN PHYSICS B, 15 (3). pp. 305-312. ISSN 0217-9792Full text not available from this repository.
Nanocrystalline NiFe2O4 powder has been prepared by an oxidative precipitation process at room-temperature and the crystallite size dependent magnetic properties have been studied. The NiFe2O4 powders prepared at room-temperature had an average crystallite size of 6 nm and showed a reduced saturation magnetisation (M-s) of 3 emu g(-1). The crystallite size was increased by heating the samples to increasingly higher temperatures. The M-s value increased from 3 to 40 emu (.) g(-1) as the crystallite size was increased from 6 to 120 nm. The samples having crystallite sizes from 6 to 20 nm were superparamagnetic at room-temperature. The Mossbauer spectrum of the 6 nm sized sample showed a broad quadruple doublet, whereas, the 40 nm sized sample showed a clear sextet pattern, with a hyperfine field Values of 466 and 504 kOe for A(tetraheral) and B(octahedral) sublattices, respectively It is shown that the saturation magnetisation and magnetic hyperfine field values are significantly reduced in nanocrystalline NiFe2O4 as a function of crystallite size.
|Item Type:||Journal Article|
|Subjects:||Q Science > QC Physics|
|Journal or Publication Title:||INTERNATIONAL JOURNAL OF MODERN PHYSICS B|
|Publisher:||WORLD SCIENTIFIC PUBL CO PTE LTD|
|Date:||30 January 2001|
|Number of Pages:||8|
|Page Range:||pp. 305-312|
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