Growth of iron cobaltoxides by atomic layer deposition

Abstract

Thin films of iron cobalt oxides with spinel-type structure are made by the atomic layer deposition (ALD) technique using Fe(thd)₃ (Hthd = 2,2,6,6-tetramethylheptane-3,5-dione), Co(thd)₂, and ozone as precursors. Pulse parameters for ALD-type growth are established and such growth can be achieved at deposition temperatures between 185 and 310 °C. Films have been deposited on amorphous soda-lime glass and single-crystalline substrates of Si(100), MgO(100), and α-Al₂O₃(001) which all provide crystalline films, but with various orientations and crystallite sizes. Application of an external magnetic field during the film growth does not influence film growth characteristics (growth rate, crystallinity, topography etc.). Magnetization data are reported for phase-pure films of spinel-type structure with composition Fe₂CoO₄.