Single‐Source Precursors for the Chemical Vapor Deposition of Iron Germanides

Abstract

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 Me2iPr2 NHC·GeCl2 · Fe(CO)4 allowed for their application as precursors under standard CVD conditions ( Me2iPr2 NHC=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.