We show that epitaxial Co2MnSi films can be fabricated on lattice-matched MgAl2O4 substrates using an ion-beam-assisted sputtering method. Low temperature growth below similar to 500 degrees C with Ar ion-beam assistance enabled high-quality Co2MnSi films with ideal saturation magnetization and highly-ordered L2(1) structures. The Co2MnSi films also demonstrated a negative anisotropic magnetoresistance of similar to 0.1% at room temperature, which is a typical characteristic of half-metals. These results suggest that ion-beam assisted sputtering is an effective method of fabricating high-quality, half-metallic Co2MnSi films at low growth temperatures. (C) 2014 Elsevier B.V. All rights reserved.