Probing the coexistence of superconductivity and ferromagnetism

We present magnetic field modulated microwave spectroscopy (MFMMS) and VSM data of a lithiated iron selenide hydroxide, [(Li$_{\mathrm{1-x}}$Fe$_{\mathrm{x}})$OH](Fe$_{\mathrm{1-y}}$Li$_{\mathrm{y}})$Se (x$=$0.2, y$=$0.08). This compound is one of the few claimed to exhibit superconductivity below 43 K together with ferromagnetism below 10 K. MFMMS is a unique technique which is highly sensitive and selective to electronic phase transistions. It allows us to probe the superconductivity and ferromagnetism at the same time in the lithiated iron selenide hydroxide. This is the first time that a microwave signature of this class of materials is presented. We compare our results to standard magnetometry measurements. This study is financially supported by the AFOSR Grant No. FA9550-12-1-0381.