23August2019

Nano-Micro Letters

Hydrothermal Synthesis and Characterization of PEG-Mn3O4 Nanocomposite

E. Karaoğlu1,*, H. Deligöz2, H. Sözeri3, A. Baykal1, M. S. Toprak4

Abstract
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Nano-Micro Letters, , Volume 3, Issue 1, pp 25-33
Publication Date (Web): April 19, 2011 (Article)
DOI:10.3786/nml.v3i1.p25-33

 

Abstract

 


Figure 1 XRD powder pattern of PEG-Mn3O4 nanocomposite.

Here, we reported on the synthesis of PEG-Mn3O4 nanocomposite (NP’s) via a hydrothermal route by using Mn(acac) 2, ethanol, NH3 and PEG-400. The crystalline phase was identified as Mn3O4. The crystallite size of the PEG-Mn3O4nanocomposite was calculated as 12 ± 5 nm from X-ray line profile fitting and the average particle size from TEM was obtained as 200 nm. This reveals polycrystalline character of Mn3O4 NP’s. The interaction between PEG-400 and the Mn3O4 NP’s was investigated by FTIR. Temperature independent AC conductivity of PEG-Mn3O nanocomposite beyond 20 kHz provides a strong evidence of ionic conduction through the structure. The conductivity and permittivity measurements strongly depend on the secondary thermal transition of nanocomposite beyond 100°C. Above that temperature, Mn3O4 particles may interact with each other yielding a percolated path that will facilitate the conduction. On the other hand, the relatively lower activation energy (Ea=0.172 eV) for relaxation process suggests that polymer segmental motions of PEG and electrons hopping between Mn2+ and Mn3+ may be coupled in the sample below 100°C. Room temperature magnetization curve of the sample does not reach to a saturation, which indicates the superparamagnetic character of the particles.As the temperature increases, the frequency at which (ε'') reaches a maximum shifted towards higher frequencies. The maximum peak was observed at 1.4 kHz for 20°C while the maximum was detected at 23.2 kHz for 90°C. 


 

Keywords

Spinels; Magnetic nanomaterials; Conductivity; Magnetic properties; Hydrothermal Synthesis

 

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