Interface Structure Of Iron Oxide Thin Films Grown On Sapphire And Single-Crystal MgO

Abstract

ABSTRACTThe ability to tailor thin film interface structure is illustrated by the growth of thin ferric oxide films using different deposition parameters. Low-pressure chemical vapor deposition (CVD) has been used to grow α-Fe2O3 on sapphire while pulsed-laser ablation (PLA) followed by low temperature oxidation has been used to grow γ-Fe2O3 on MgO. The structure of the films and of the film-substrate interfaces has been characterized using transmission electron microscopy (TEM) and selected-area diffraction (SAD) in plan view. The different deposition techniques lead not only to the growth of two different polymorphs of ferric oxide but also to different growth mechanisms and film-substrate interface structures. In addition, changes in the thermodynamic conditions during deposition can give rise to different interface structures between the individual structural domains of the film.