The project is dedicated to the preparation of magnetic nanoparticles (NP) within the diameter range 1 – 15 nm as well as to their detailed structural and magnetic characterization with emphasis on direct analysis of single NP. Within the project three topics can be distinguished:
Preparation of magnetic NP based on the selforganization of inverse micelles
Here, we focus on binary alloys like FePt, CoPt and CoSm with high magneto-crystalline anisotropy energies. The specific goal is controlling the particle size as well as the interparticle distance.
Structural and magnetic characterization of single nanoparticles
Emphasis is made on high spatial and high energy resolution Transmission Electron Microscopy (TEM) analysis based on aberration corrected high resolution TEM imaging and electron energy loss spectroscopy to unravel the size-dependent crystallographic and electronic structure of the nanoparticles . Magnetic information on the nanoparticles will be gained using electron holography and Lorentz microscopy.
Magnetic characterization of particle-ensembles
For this purpose, preferentially X-ray Magnetic Circular Dichroism (XMCD) measurements are performed at the synchrotron BESSY II. This technique delivers not only hysteresis curves of particle arrays, but additionally orbital and spin moments of the elements constituting the particles.