TEA CO2 laser‐induced dielectric breakdown of an equimolar mixture of gaseous stannane and germane in Ar allows decomposition of both metal hydrides and chemical vapour deposition of the nanostructured Ge/Sn films. Analysis of the films by FTIR and Raman spectroscopy, X‐ray diffraction analysis and electron microscopy revealed nanoregions of crystalline Sn and Sn‐rich Ge/Sn alloys surrounded by an amorphous Ge/Sn phase. The crystalline Ge/Sn nanoalloys contain different amounts of Sn incorporated into the Ge lattice and undergo changes in composition at temperatures as low as 200 °C.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)