The reaction of GeCl2 ⋅ 1,4-dioxane with Fe2(CO)9 gives [Cl2GeFe(CO)4]2, Cl2Ge[Fe2(CO)8]Ge[Fe2(CO)8] or Ge[Fe2(CO)8]2, depending on the educt ratio. [Cl2GeFe(CO)4]2, Ge[Fe2(CO)8]2 and Me₂iPr₂NHC ⋅ GeCl2 ⋅ Fe(CO)4 were characterized in their thermal decomposition behavior and applied as single source precursors in chemical vapor deposition, resulting in FexGe1-x thin films.
Binary iron-germanium phases are promising materials in magnetoelectric, spintronic or data storage applications due to their unique magnetic properties. Previous protocols for preparation of FexGey thin films and nanostructures typically involve harsh conditions and are challenging in terms of phase composition and homogeneity. Herein, we report the first example of single source chemical vapor deposition (CVD) of FexGey films. The appreciable volatility of [Ge[Fe2(CO)8]2], [Cl2GeFe(CO)4]2 and Me₂iPr₂NHC ⋅ GeCl2 ⋅ Fe(CO)4 allowed for their application as precursors under standard CVD conditions (Me₂iPr₂NHC=1,3-diisopropoyl-4,5-dimethylimidazol-2-ylidene). The thermal decomposition products of the precursors were characterized by TGA and powder XRD. Deposition experiments in a cold-wall CVD reactor resulted in dense films of FexGey. During the optimization of synthetic conditions for precursor preparation the new iron-germanium cluster Cl2Ge[Fe2(CO)8]Ge[Fe2(CO)8] was obtained in experiments with a higher stoichiometric ratio of GeCl2 ⋅ 1,4-dioxane vs. Fe2(CO)9.Zum Volltext