Crystallization behavior of iron-based amorphous nanoparticles prepared sonochemically

Naoya Enomoto; Shingo Hirata; Miki Inada; Katsuro Hayashi

doi:10.1016/j.ultsonch.2016.04.033

Crystallization behavior of iron-based amorphous nanoparticles prepared sonochemically

Ultrason Sonochem. 2017 Mar;35(Pt B):563-568. doi: 10.1016/j.ultsonch.2016.04.033. Epub 2016 May 6.

Authors

Naoya Enomoto¹, Shingo Hirata², Miki Inada², Katsuro Hayashi²

Affiliations

¹ Department of Applied Chemistry, Faculty of Engineering, Kyushu University, Japan. Electronic address: enomoto@cstf.kyushu-u.ac.jp.
² Department of Applied Chemistry, Faculty of Engineering, Kyushu University, Japan.

PMID: 27184926
DOI: 10.1016/j.ultsonch.2016.04.033

Abstract

In general, a rapid quenching is required to obtain an amorphous metal. It is known that an intensive ultrasonication generates a very high temperature within cavitation bubbles in a very short moment, which enables a rapid quenching process in a liquid phase synthesis. In this study, the sonochemically-derived "amorphous iron" from Fe(CO)₅ was carefully examined by XRD, TEM, TG-DTA. The product was found to be an amorphous containing a certain amount (∼15%) of volatile component that can be removed by heating in a nitrogen flow. After annealed in the inert atmosphere at 600°C, cooled down to room temperature, and then exposed in air (oxygen), the sample showed a strong exotherm accompanied by a weight gain. This is due to oxidation of fine metallic iron. Experimental operations of such a reactive material were examined.

Keywords: Iron carbonyl; Rapid quenching; Sonochemical synthesis.