Akademik Veri Yönetim Sistemi
Journal of Alloys and Compounds, cilt.502, sa.1, ss.199-205, 2010 (SCI-Expanded)
We report on the synthesis of (polyvinylpyrrolidone) PVP-Mn 3O4 nanocomposite via a polyol route. Crystalline phase was identified as Mn3O4 and the crystallite size was obtained as 6±1 nm from X-ray line profile fitting. Average particle size of 6.1±0.1nm obtained from TEM analysis reveals nearly single crystalline nature of these nanoparticles in the composite. The capping of PVP around Mn3O4 nanoparticles was confirmed by FT-IR spectroscopy, the interaction being via bridging oxygens of the carbonyl (C=O) and the nanoparticle surface. TC and TB for PVP-Mn3O4 nanocomposite were observed at 42K and 28.5 K, respectively. The sample has hysteresis with small coercivity and remanent magnetization at 40 K, resembling the superparamagnetic state. ac conductivity measurements on PVP-Mn3O4 nanocomposite revealed a conductivity in the order of 10-7 S cm-1 at lower frequencies. The conductivity change with respect to frequency can be explained by electronic exchange occurring between Mn+2 and Mn +3 existing in sublattice of spinel lattice. © 2010 Elsevier B.V. All rights reserved.