Epitaxial composites of Sr ferrite and hematite grown on Al 2 O 3 by electron beam deposition and heat treatment

We prepared Sr-ferrite films by heat treating spinel ferrite films containing 2 at. % of Sr at 1123 K for 1 h under an oxygen pressure of 4 × 10 − 3 Pa . The spinel ferrites were epitaxially grown on Al 2 O 3 (00.1) substrates by electron beam deposition using Sr ferrite and Sr O 2 as sources. Data measured with a vibrating sample magnetometer revealed that the film exhibited a magnetic uniaxial anisotropy axis perpendicular to the film plane and the coercivity was 2.5 kOe . Measurements with x-ray diffraction and electron diffraction revealed that the films were composites of Sr ferrites and hematites, and the Sr ferrites and hematites had epitaxially grown in the form of layers. The epitaxial relations between Sr ferrite, Fe 2 O 3 , and Al 2 O 3 were [ 00.1 ] Sr ferrite || [ 00.1 ] Fe 2 O 3 || [ 00.1 ] Al 2 O 3 and [ 1 − 1.0 ] Sr ferrite || [ 11.0 ] Fe 2 O 3 || [ 11.0 ] Al 2 O 3 .