Study of magnetic ground state in infinite-layer nickelates

Since the discovery of superconductivity in infinite-layer nickelate thin films several questions have arisen about the role of the SrTiO3(STO)-capping-layer in the stabilization of the infinite-layer phase. Recently, a muon spin rotation/relaxation study performed on capped samples, pointed out that a robust magnetic ground state (up to 150 K) is coexisting with superconductivity, as in iron pnictides compounds. Here, we propose a comprehensive study of the electronic and magnetic properties of Nd1-xSrxNiO2 (x=0, 0.05, 0.2) thin films with/without STO-capping-layer by polarized resolved x-ray absorption spectroscopy. We aim at providing an element and orbital resolved study of the magnetism in these compounds as a function of the STO-capping-layer. X-ray magnetic circular dichroism measurements will be performed at both Ni L- and Nd M-edges as a function of the temperature and of the external applied magnetic fields to ascertain the nature of the magnetism in this system.