| A single-step synthesis of iron germanate (Fe2GeO4) nanoparticles with an average crystallite size of about 11 nm synthesized via mechanochemical processing of the α-Fe2O3/Fe/GeO2 mixture at room temperature is reported. Due to the ability of 57Fe Mossbauer spectroscopy to discriminate between probe nuclei on inequivalent crystallographic sites provided by the spinel structure, valuable insight into the local cation disorder in mechanosynthesized Fe2GeO4 is obtained. In contrast to the bulk Fe2GeO4 with a normal spinel structure (λ = 0), the nanocrystalline mechanosynthesized Fe2GeO4 adopts a partly inverse spinel structure with a nonequilibrium cation distribution (λ≅ 0.67) and deformed polyhedron geometries. Quantitative microstructural information on the disordered cation arrangement provided by Mossbauer spectroscopy is complemented by XRD and TEM investigations revealing the nanoscale nature of the mechanosynthesized material. |
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