Nanocrystalline orthoferrite powders: Synthesis and magnetic properties
Rajendran, M. and Bhattacharya, A. K.. (2006) Nanocrystalline orthoferrite powders: Synthesis and magnetic properties. JOURNAL OF THE EUROPEAN CERAMIC SOCIETY, 26 (16). pp. 3675-3679. ISSN 0955-2219Full text not available from this repository.
Official URL: http://dx.doi.org/10.1016/j.jeurceramsoc.2006.01.0...
Nanocrystalline orthoferrite powders were synthesised at low temperatures by employing an aqueous sot-get process. Colloidal sols and water re-dispersible gels of orthoferrite precursors were prepared by room-temperature processing of inexpensive metal salts. The average diameter (Z(av)) of the precursor particles was in the size range from 4 to 7 nm; the diameters had a narrow size distribution. Water re-dispersible translucent gel monoliths were obtained by concentrating the aqueous sols followed by drying them under reduced pressure (10(-2) Torr) at room temperature. The sol-gel transition was found to be completely reversible. Nanocrystalline fine powders of orthoferrites of general formula, LnFeO(3) (Ln = La, Sm, Gd, Dy, Er, Yb and Y) having a crystallite size of about 25 nm were prepared by heating the gel precursors at 650-700 degrees C in air. Powder X-ray diffraction and thermogravimetry, respectively, were employed to identify perovskite phase formation and delineate thermal events that lead to gel to crystallite conversion. Magnetic measurements were carried out on the resultant powders at room temperature and down to 40 K. Nanocrystalline orthoterrite powders exhibited weak ferromagnetic behaviour, and reduced magnetic moments. (c) 2006 Elsevier Ltd. All rights reserved.
|Item Type:||Journal Article|
|Subjects:||T Technology > TP Chemical technology|
|Journal or Publication Title:||JOURNAL OF THE EUROPEAN CERAMIC SOCIETY|
|Publisher:||ELSEVIER SCI LTD|
|Number of Pages:||5|
|Page Range:||pp. 3675-3679|
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