Physics of magnetic impurity states in Gd monopnictides

Physical properties of magnetic impurity states in Gd monopnictides are studied in detail through anomalous transport and magnetic properties. Due to strong cancellation of d-f exchange by p-f mixing, the systems stay in the weak 4f polarization regime, in contrast with trapped magnetic polaron in Eu chalcogenides. Anomalous magnetic properties are explained very well by weak magnetic impurities without an interaction between them. Main defects in the main part of samples are thought to be nearly equal amounts of Gd and pnictogen vacancies keeping the stoichiometry good. The similarity with the weak magnetic polaron liquid in Ce monopnictides is emphasized. The obtained results are consistent with those shown in earlier papers for pure samples.