The topographic and magnetic surface structure of a natural single crystal of magnetite (Fe ₃ O ₄ ), a common mineral, has been studied from the submicrometer scale down to the atomic scale with a scanning tunneling microscope having nonmagnetic tungsten as well as ferromagnetic iron probe tips. Several different (001) crystal planes were imaged to atomic resolution with both kinds of tips. A selective imaging of the octahedrally coordinated Fe B-sites in the Fe-O planes, and even a selective imaging of the different magnetic ions Fe ²⁺ and Fe ³⁺ , has been achieved, demonstrating for the first time that magnetic imaging can be realized at the atomic level.

For the first time the surface structure of an icosahedral quasicrystal could be resolved in direct space by scanning tunneling microscopy. The surface was found to form terraces with their normals being parallel to a fivefold axis. On the terraces fivefold stars and pentagonal holes were observed. Both the step heights and the distances between pentagonal holes obey Fibonacci sequences. The distribution of the holes locally resembles a Penrose tiling and is correlated up to long distances indicating a quasiperiodic order. A simple model yields an autocorrelation function very similar to the experiment.

An angle dependent analysis of the planar Hall effect (PHE) in nanocrystalline single-domain Co60Fe20B20 thin films is reported. In a combined experimental and theoretical study we show that the transverse resistivity of the PHE is entirely driven by anisotropic magnetoresistance (AMR). Our results for Co60Fe20B20 obtained from first principles theory in conjunction with a Boltzmann transport model take into account the nanocrystallinity and the presence of 20~at.\,% boron. The ab~initio AMR ratio of 0.12% agrees well with the experimental value of 0.22%. Furthermore, we experimentally demonstrate that the anomalous Hall effect contributes negligibly in the present case.

Magnetic molecules are potential functional units for molecular and supramolecular spintronic devices. However, their magnetic and electronic properties depend critically on their interaction with metallic electrodes. Charge transfer and hybridization modify the electronic structure and thereby influence or even quench the molecular magnetic moment. Yet, detection and manipulation of the molecular spin state by means of charge transport, that is, spintronic functionality, mandates a certain level of hybridization of the magnetic orbitals with electrode states. Here we show how a judicious choice of the molecular spin centres determines these critical molecule–electrode contact characteristics. In contrast to late lanthanide analogues, the 4f-orbitals of single bis(phthalocyaninato)-neodymium(III) molecules adsorbed on Cu(100) can be directly accessed by scanning tunnelling microscopy. Hence, they contribute to charge transport, whereas their magnetic moment is sustained as evident from comparing spectroscopic data with ab initio calculations. Our results showcase how tailoring molecular orbitals can yield all-electrically controlled spintronic device concepts.

We study interlayer exchange coupling in epitaxial $\mathrm{Fe}/{\mathrm{Fe}}_{0.56}{\mathrm{Si}}_{0.44}/\mathrm{Fe}$ trilayers. Iron-silicide spacers with high structural and compositional homogeneity for thicknesses up to 34 Å are grown by coevaporation from two electron-beam sources. The coupling strength oscillates with spacer thickness for temperatures from 20 to 300 K with two antiferromagnetic maxima at 12 and 26 Å, and it clearly increases with decreasing temperature down to 80 K. We conclude that the coupling across ordered ${\mathrm{Fe}}_{1-x}{\mathrm{Si}}_x$ ( $x\approx 0.5$) is described by the conventional theory of interlayer coupling across metallic spacers.