Iron
Introduction
Iron nanoparticles are both interesting for magnetic as well as chemical applications. Bulk iron is magnetic and has the highest saturation magnetization of all the transition metals. The diameter where the iron nanoparticles start to undergo spontaneous thermal fluctuations at room temperature is around 8 nm and the single domain threshold lies at 10 nm. Nanosizing iron is advantageous in magnetic recording media because it leads to high recording densities. In which case nanorods are used. Spherical nanoparticles are used in medical applications, for MRI contrast enhancement and hyperthermia. In these cases, Fe is exposed to an oxidizing environment, so instead magnetic iron-oxides are used.
For chemical applications, iron nanoparticles are used in inert or reducing atmospheres. They are widely used in the Fisher-Tropsch synthesis where they catalyze the breaking of C-C bonds. See the reference article for an extensive overview of all (possible) uses. The metal-insulator transition is expected to be around 110 atoms, corresponding to 1 nm nanoparticles.
Basic data
| Name | Iron (Fe) |
|---|---|
| Configuration | 4s2 3d6 |
| Electrons | 26 |
| Group | 8 |
| Abundance | 2.3% |
| Magnetic type | ferromagnetic |
| Melting point | 1538 ℃ |
| Boiling point | 2861 ℃ |
Interesting reads
- Ambient Plasma Synthesis of Si-Fe Hollow Nanoparticles and Their Biocompatibility and Lithium Storage Capacity synthesis doi:10.1002/admi.201300134
- Synthesis, Properties, and Applications of Iron Nanoparticles functionality doi:10.1002/smll.200500006
Key trends at the nanoscale
Applications
The pie chart presented here is based on the distribution of research literature across various fields of application research over the period 1992 to 2017. The value listed is the number of papers discussing Iron related to nanoparticles, sorted by application field. This gives an indication which applications are being or have been researched and where the core interest is. However, the distribution does not correct for the total publications in a given application field. So, a high score for a given application field indicates there is considerable interest in the element in that field, but it may also mean the field itself has considerable more publications than other fields. Therefore, the pie chart gives a general overview only. The application fields themselves are discussed in more detail on our Nanoparticles page.
Additionally, the total number of publications provides some insight in the amount of research into Iron used in nanoparticles in general. Typically, a well-researched element will show 1000 or more publications over the 1992-2017 period.
Alloys and composites
The graph below presents an analysis of literature on core-shell, alloy and composite particles with iron as a component of such nanoparticles. It shows possible combinations for alloy or composite nanoparticles and reflects research interest during the 1992-2017 period.