Preparation and physical properties of EuO nanocrystals using Eu(II)-exchanged zeolite X as a precursor

The cation-exchange of zeolite X with divalent europium has been achieved using a methanol solution containing Eu(II) prepared by photochemical reduction of Eu(III). Emission spectra have confirmed that the valence of europium ion in the ion-exchanged zeolite X was divalent. A blue shift of emission spectra was observed after exposing Eu(II)X to air at room temperature. TEM have revealed the formation of EuO nanocrystals with average size of 4.2 nm on the outer surface of Eu(II)X. EuO nanocrystals show ferromagnetism accompanied by photo-response magnetism under UV irradiation.