All compounds present in the lithium-silicon binary phase diagram were synthesized and analyzed by electron energy-loss spectroscopy. In order to limit beam damage, and to develop a fast and local method of characterizing silicon negative electrodes, the valence energy-loss spectrum region was investigated, in particular the very intense plasmon peak in these alloys. Experimental spectra are in strong agreement with theoretical ones obtained from density functional theory. These results constitute a database for Li(x)Si alloys' plasmon energies. The method is applied to the study of the first discharge of a silicon electrode, thus identifying a Li(2.9+/-0.3)Si phase in equilibrium with Si on the voltage plateau. A nucleation process of this phase in the pristine Si is revealed, as well as a possible over-lithiation beyond the end of discharge Li(15)Si(4) crystalline phase.

(2016) Surface and electronic structure of SmB through scanning tunneling microscopy, Philosophical Magazine, 96:31, 3262-3273, DOI: 10.1080/14786435.2016 ABSTRACTSmB 6 , a so-called Kondo insulator, is recently discussed as a candidate material for a strong topological insulator. We present detailed atomically resolved topographic information on the (0 0 1) surface from more than a dozen SmB 6 samples. Atomically flat, in situ cleaved surfaces often exhibit B-and Sm-terminated surfaces as well as reconstructed and non-reconstructed areas coexisting on different length scales. The terminations are unambiguously identified. In addition, electronic inhomogeneities are observed which likely result from the polar nature of the (0 0 1) surface and may indicate an inhomogeneous Sm valence at the surface of SmB 6 . In addition, atomically resolved topographies on a (1 1 0) surface are discussed. ARTICLE HISTORY

Boron carbide, the simple chemical combination of boron and carbon, is one of the best-known binary ceramic materials. Despite that, a coherent description of its crystal structure and physical properties resembles one of the most challenging problems in materials science. By combining ab initio computational studies, precise crystal structure determination from diffraction experiments, and state-of-the-art high-resolution transmission electron microscopy imaging, this concerted investigation reveals hitherto unknown local structure modifications together with the known structural alterations. The mixture of different local atomic arrangements within the real crystal structure reduces the electron deficiency of the pristine structure CBC+B , answering the question about electron precise character of boron carbide and introducing new electronic states within the band gap, which allow a better understanding of physical properties.