Seminars Archive

Crystal local field studies through resonant reflectivity and absorption: measurements and calculations ab initio

Abstract
The study of resonant spectra at the atomic thresholds allows to quantify the local crystal field through its effects on the shape, the relative intensities of the peaks, and the polarization dependence. As the photons can probe deep layers, the reflectivity measurement of these resonances enlarges the field of study to multilayered structures. Being the reflectivity a coherent phenomenon one can also study the magnetic order. We discuss several measured systems and the comparison with theory: the code ONDA (electromagnetic calculations) and AMARCORD (ab initio calculations of an "Atomo Magnetico Asferico in Reticolo Cristallino Orientato alla Ricerca sul Dicroismo")