In this letter, we report the synthesis of epitaxial SnxGe1−x/Ge/Si(001) with compositions up tox=0.34 by ion‐assisted molecular beam epitaxy with 30–100 eV Ar+ions produced by an electron cyclotron resonance ionization source with ion to atom flux ratios of the order of unity in the substrate temperature range of 120–200 °C. High flux low energy ion beam irradiation greatly inhibits Sn segregation without interrupting epitaxy. ©1996 American Institute of Physics.