Monoclinic B-phase erbium sesquioxide (Er2O3) thin films by filtered cathodic arc deposition

Er2O3 sesquioxide thin films in the uncommon, monoclinic phase were produced for the first time by filtered cathodic arc deposition on Eurofer steel substrates. This was achieved by applying a sample bias of −250 V and deposition temperatures ⩽400 °C. X-ray diffraction texture analysis revealed a strong preferred orientation of the B-phase crystallites. Deposition at 600 °C without bias voltage resulted in thin films showing the regular cubic phase. A dense, columnar structure was found for both phases by scanning transmission electron microscopy.