title: Phase discrimination through oxidant selection in low-temperature atomic layer deposition of crystalline iron oxides.
abstract: Control over the oxidation state and crystalline phase of thin-film iron oxides was achieved by low-temperature atomic layer deposition (ALD), utilizing a novel iron precursor, bis(2,4-methylpentadienyl)iron. This low-temperature (T = 120 °C) route to conformal deposition of crystalline Fe3O4 or α-Fe2O3 thin films is determined by the choice of oxygen source selected for the second surface half-reaction. The approach employs ozone to produce fully oxidized α-Fe2O3 or a milder oxidant, H2O2, to generate the Fe(2+)/Fe(3+) spinel, Fe3O4. Both processes show self-limiting surface reactions and deposition rates of at least 0.6 Å/cycle, a significantly high growth rate at such mild conditions. We utilized this process to prepare conformal iron oxide thin films on a porous framework, for which α-Fe2O3 is active for photocatalytic water splitting.
authors: Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439, United States.
authors: Shannon C
authors: SC
authors: Riha
authors: Joy M
authors: JM
authors: Racowski
authors: Michael P
authors: MP
authors: Lanci
authors: Jeffrey A
authors: JA
authors: Klug
authors: Adam S
authors: AS
authors: Hock
authors: Alex B F
authors: AB
authors: Martinson