We propose a method to grow metal tetraphenyl porphyrin (MTPP) molecular layers where a long-range structural and magnetic order can be achieved simultaneously and at room temperature by a proper treatment of the ferromagnetic substrate. We focus in particular on the oxygen-passivated Fe(001)-p(1 × 1)O surface, where MTPP molecules (with M=Co and Ni) arrange by forming square commensurate overlayers. Spin-resolved photoemission detects a clear spin-splitting of CoTPP electronic states, while no magnetic response is obtained from NiTPP, as expected from the electronic configuration of the respective free molecules. We link these observations to the decoupling action of oxygen at the interface, whose effect is to enhance the molecular diffusivity and tune the electronic interaction with the substrate electronic structure.

In this paper we focus on the structural, electronic, and magnetic properties of Ni tetra-phenyl-porphyrins (NiTPP) grown on top of Fe(001)–p(1 × 1)O. Ordered thin films of metal TPP molecules are potentially interesting for organic electronic and spintronic applications, especially when they are coupled to a ferromagnetic substrate. Unfortunately, porphyrin layers deposited on top of ferromagnetic substrates do not generally show long-range order. In this work, we provide evidence of an ordered disposition of the organic film above the iron surface and we prove that the thin layer of iron oxide decouples the molecules from the substrate, thus preserving the molecular electronic features, especially the HOMO-LUMO gap, even when just a few organic layers are deposited. The effect of the exposure to molecular oxygen is also investigated and an increased robustness against oxidation with respect to the bare substrate is detected. Finally, we present our results for the magnetic analysis performed by spin resolved spectroscopy, finding a null magnetic coupling between the molecules and the substrate.

Despite decades of reports of weak magnetic field effects in biology across the tree of life and on a broad range of cell types, the evidence to date remains met with skepticism. To remedy this, we present open-data, large-scale, and varied morphological evidence that Xenopus laevis embryo development is accelerated in a well-engineered, environmentally-calibrated hypomagnetic field of less than 1 nT. These data imply that basal tadpole physiology can sense and react to the absence of Earth’s minute magnetic field of approximately 50 µ T. The effect is significant, as demonstrated by a variety of statistical measures. As no definitive biophysical mechanism has been identified to account for its occurrence, this study raises the question of which mechanism provides the most plausible explanation. How that question is answered may have implications in a variety of fields, including human health, behavioral ecology, and space exploration.

Shaping the morphology of oxide nanolayers is of paramount importance in tailoring their physical and chemical properties. Here, the influence of a two dimensional graphene buffer layer on the growth of Fe oxide has been investigated by comparing the oxide deposition on a Ni(111) and a graphene/Ni(111) substrate. Scanning tunneling microscopy images acquired at a mesoscopic scale indicate that Fe oxide grows layer-by-layer on the bare Ni(111) surface, while the nucleation of three-dimensional clusters is induced by graphene. Atomically resolved images reveal that Fe oxide adopts an in-plane lattice constant similar to that of the FeO(111) surface when deposited on Ni(111) and graphene/Ni(111), indicating in both cases, a weak interaction between the overlayer and the substrate. Accordingly, it is suggested that the different growth mode is mainly driven by the graphene-induced lowering of the substrate surface free energy.