Full-text resources of PSJD and other databases are now available in the new Library of Science.
Visit https://bibliotekanauki.pl
Preferences help
Polish version English version Language
enabled [disable] Abstract
Number of results

Results found: 2

Number of results on page
first rewind previous Page / 1 next fast forward last

Search results

help Sort By:

help Limit search:
first rewind previous Page / 1 next fast forward last
1
Content available remote

Influence of Iron Nanowires Oxidation on Their Semiconducting Properties

100%
Krajewski M., Gołasa K., Wasik D.
Acta Physica Polonica A
|
2016
|
vol. 129
|
issue 1a
A-135-A-137
EN
The main aim of this work was to study the impact of thermal annealing on the structure of iron oxide shell covering iron nanowires in relation to their semiconducting properties. Studied nanomaterial has been produced via a simple chemical reduction in an external magnetic field and then it has been thermally-treated at 400°C, 600°C and also 800°C in a slightly oxidizing argon atmosphere. Annealed iron nanowires have been characterized by means of the Raman spectroscopy and photoluminescence in order to study the structure of iron oxide shell and its influence on semiconducting properties of the whole nanostructure. According to obtained experimental results, the composition of iron oxide shell covering the studied nanomaterial is changing with annealing temperature. The thermal treatment at 400°C leads to oxidation of iron coming from the core of nanomaterial and formation of a mixture of Fe₃O₄ and α -Fe₂O₃ on the surfaces of nanowires, while annealing at higher temperatures results in further oxidation of iron as well as the phase transformation of previously created Fe₃O₄ into the most thermodynamically stable form of iron oxide at ambient conditions - α -Fe₂O₃. This oxide has a major impact on the semiconducting properties of studied nanomaterial. Thereby, the measurements of photoluminescence enabled to estimate the bandgap of bulk and surface layer at about 1.8 eV and 2.1 eV, respectively.
2
Content available remote

Phase Analysis of Magnetic Inclusions in Nanomaterials Based on Multiwall Carbon Nanotubes

64%
Brzózka K., Krajewski M., Małolepszy A., Stobiński L., Szumiata T., Górka B., Gawroński M., Wasik D.
Acta Physica Polonica A
|
2017
|
vol. 131
|
issue 4
863-865
EN
Functionalized multiwall carbon nanotubes as well as nanocomposite based on that material covered by nanoparticles composed of iron oxides were the subject of investigations. In order to identify all iron-bearing phases including those reported on the base of previous X-ray diffraction measurements, the transmission Mössbauer spectroscopy was utilized. The experiments were carried out both at room temperature and also at low temperatures. It was stated that in the investigated nanotubes some impurities were present, originating from the catalyst remains, in form of Fe-C and α -Fe nanoparticles. The Mössbauer spectra collected for the nanocomposite showed a complex shape characteristic of temperature relaxations. The following subspectra related to iron-based phases were identified: sextet attributed to hematite, with hyperfine magnetic field reduced due to the temperature relaxations, sextet corresponding to iron carbide as well as two doublets linked to superparamagnetic hematite and ferrihydrites.
first rewind previous Page / 1 next fast forward last
JavaScript is turned off in your web browser. Turn it on to take full advantage of this site, then refresh the page.