Complex formation and background impurity of Oxygen in the PbTe:Eu doped crystals grown from melt by the Bridgman method

► Magnetization and magnetic susceptibility of the PbTe:Eu samples are investigated. ► Formation of the complexes Eu with the background Oxygen impurities is revealed. ► Complexes dominate in the incipient section of the doped ingots. ► Single centers of Eu ions are the only centers of the impurity in the ingot end. ► Complexes can convert the crystal matrix from diamagnetic to paramagnetic state.