Structural and magnetic properties of iron nanowires and iron nanoparticles fabricated through a reduction reaction.

Marcin Krajewski,Hong Ming Lin,Jolanta Borysiuk,Katarzyna Brzozka,Anna Slawska-Waniewska,Sabina Lewinska,Natalia Nedelko,Dariusz Wasik,Wei Syuan Lin

doi:10.3762/bjnano.6.167

Abstract

The main goal of this work is to study the structural and magnetic properties of iron nanowires and iron nanoparticles, which have been fabricated in almost the same processes. The only difference in the synthesis is an application of an external magnetic field in order to form the iron nanowires. Both nanomaterials have been examined by means of transmission electron microscopy, energy dispersive X-ray spectrometry, X-ray diffractometry and Mössbauer spectrometry to determine their structures. Structural investigations confirm that obtained iron nanowires as well as nanoparticles reveal core–shell structures and they are composed of crystalline iron cores that are covered by amorphous or highly defected phases of iron and iron oxides. Magnetic properties have been measured using a vibrating sample magnetometer. The obtained values of coercivity, remanent magnetization, saturation magnetization as well as Curie temperature differ for both studied nanostructures. Higher values of magnetizations are observed for iron nanowires. At the same time, coercivity and Curie temperature are higher for iron nanoparticles.

Highlights

Iron-based nanostructures attract the attention of a vast amount of scientists from all over the world
It is worth to emphasize that the only difference in the fabrication processes of the two investigated nanostructures, iron nanowires and iron nanoparticles, is an application of an external magnetic field in the case of iron nanowires
Possible structures of iron nanowires and iron nanoparticles have been determined, which are very similar. Both nanomaterials reveal core–shell structures and are constructed of crystalline α-Fe cores, which are covered by a layered structure composed of: amorphous iron, amorphous iron oxides and distorted iron oxides

Summary

Introduction

Iron-based nanostructures attract the attention of a vast amount of scientists from all over the world. Somehow, this is related to the properties and abundance of iron in the environment. Adding that iron nanomaterials are relatively inexpensive, a lot of them are biocompatible and low-toxic, it makes them very interesting from an application point of view. They have been applied in many biomedical applications including magnetic resonance imaging (MRI) contrast enhancements [1], Beilstein J. In the case of drug delivery systems nanostructures need to exhibit rather superparamagnetic behaviour with low coercivity. It is very important to study different nanostructures to know their properties and to match them to the adequate applications

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Results

Conclusion