Synthesis, structural and magnetic properties of nanostructured Ca0.9Gd0.1MnO3 obtained by modified glycine nitrate procedure (MGNP)
Prekajski, Marija D.
Radosavljević-Mihajlović, Ana S.
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Ca0.9Gd0.1MnO3 nanopowders with perovskite type crystal structure were synthesized by modified glycine nitrate procedure. Nanopowders were prepared by combining glycine with metal nitrates and/or metal acetates in their appropriate stoichiometric ratios. Modification of the procedure was performed by partial replacement of nitrates by acetates, in order to control the burn-up reaction. Obtained Ca0.9Gd0.1MnO3 powders were calcinated in the temperature interval from 850 degrees C to 950 degrees C for 10 min. Properties such as phase evolution, lattice parameters, chemical composition and magnetic properties were monitored by DTA, X-ray diffraction, SEM/EDS and magnetic measurements. Magnetic measurements performed at the sample with the smallest crystallite size showed that a 10% of Gd3+ substituted Ca2+ ions changes antiferromagnetic properties of CaMnO3 by the introduction of ferromagnetic interaction due to a double exchange between Mn3+ and Mn4+ ions. Presence of competing interacti...ons and their randomness lead to a formation of a spin glass state below Neel temperature T-N = 110 K. From the high temperature magnetic susceptibility measurements effective magnetic moment of manganese ions is determined which lies between the values for Mn3+ and Mn4+ ions. (C) 2011 Elsevier Ltd and Techna Group S.r.l. All rights reserved.