The formation and magnetism of iron nanostructures on ordered polymer templates

K Schlage,R Rüffer,U Vainio,S Couet,S V Roth,R Röhlsberger,P Müller-Buschbaum,M M Abul Kashem

doi:10.1088/1367-2630/14/4/043007

Abstract

We have followed the self-assembly of a magnetic antidot array during Fe sputter deposition onto a highly ordered, nanostructured polymer template by using a new kind of synchrotron radiation three-dimensional x-ray microscopy. The structural growth, chemical state (the formation of oxides) and the magnetic transition were determined in situ with 0.1 nm spatial resolution, revealing the excellent properties of polymer templates for a simple self-assembled large-scale fabrication of nanomagnetic systems tunable in size and spatial arrangement. Our method allows us to establish stability limits of novel magnetic nanostructures for high-density magnetic recording in a quantitative manner.

Highlights

(NRXR) and nuclear forward scattering (NFS) of synchrotron radiation at 14.4 keV resonance of the 57Fe Mossbauer isotope were combined to follow the growth of the iron nanostructure, to detect its chemical state and to investigate the magnetic transition from the nonmagnetic to an ordered ferromagnetic state
The in situ experiment started with the characterization of the virgin nanoporous polymer template using Grazing-incidence small angle x-ray scattering (GISAXS)
The diameter of the empty cylinders was determined to be 28.2±0.2 nm. This quantifies the relative surface area of the holes to about 30%. These findings are in good agreement with atomic force microscopy (AFM) measurements (figure 2(d)), which locally probe the template

Summary

Introduction

(NRXR) and nuclear forward scattering (NFS) of synchrotron radiation at 14.4 keV resonance of the 57Fe Mossbauer isotope were combined to follow the growth of the iron nanostructure, to detect its chemical state (the formation of oxides) and to investigate the magnetic transition from the nonmagnetic to an ordered ferromagnetic state. This new approach offers sensitivity to all the key parameters over a wide dynamic range from sub-nm to μm length scales, providing comprehensive information not accessible with conventional microscopy. This way we realize the arrangement of ordered vertical nanopores embedded in a flat PS matrix

Methods

Results

Conclusion