Thermal stability of nanocrystalline ε-Fe2O3

0429198 - ÚACH 2015 RIV HU eng J - Journal Article
Brázda, Petr - Večerníková, Eva - Pližingrová, Eva - Lančok, Adriana - Nižňanský, D.
Thermal stability of nanocrystalline ε-Fe2O3.
Journal of Thermal Analysis and Calorimetry. Roč. 117, č. 1 (2014), s. 85-91. ISSN 1388-6150. E-ISSN 1588-2926
R&D Projects: GA ČR GAP204/10/0035
Institutional support: RVO:61388980
Keywords : ε-Fe2O3 * Differential thermal analysis * Evolved gas analysis * Infrared spectroscopy * Thermogravimetry * X-ray powder diffraction
Subject RIV: CA - Inorganic Chemistry
Impact factor: 2.042, year: 2014

Thermal behavior of highly crystalline ε-Fe2O3 nanoparticles of different apparent crystallite sizes was characterized using thermogravimetry, differential thermal analysis, and analysis of evolved gas by mass spectrometry. Phase composition of the samples was monitored ex situ by X-ray powder diffraction. The results show that the thermal stability of this metastable iron oxide polymorph decreases with increasing particle size. For the particle diameter of 19(2) nm, the transformation temperature was equal to 794(5) °C, while for 28(2) nm only 755(10) °C. Surface of the nanoparticles contained adsorbed water and carbon dioxide. Elimination of these species proceeds in two steps. Water is removed at temperatures below 200 °C and CO2 in the temperature range between 200 and 450 °C.
Permanent Link: http://hdl.handle.net/11104/0238449