The compound Fe$_4$Si$_2$Sn$_7$O$_{16}$ has a hitherto unique crystal structure, consisting of ionic oxide layers based on edge-sharing FeO$_6$ and Sn$^{4+}$O$_6$ octahedra alternating with layers of intermetallic character based on FeSn$^{2+}_6$ octahedra, separated by covalent SiO$_4$ tetrahedra. The ionic layers contain kagomé lattices of magnetic Fe$^{2+}$ cations (octahedral crystal...
The surfaces of Sb2Te3 topological insulator crystals were implanted using a 40 keV chromium ion beam at the Centre for Accelerator Science, ANSTO. The resulting chemical structure was studied using atomic-resolution transmission electron microscopy and soft X-ray absorption spectroscopy. A thin magnetic crystalline region is formed near the surface. A uniform valence state of Cr3+ is...