Low expansion in [(Fe0.9Co0.1)0.72B0.24Nb0.04]95.5Y4.5 bulk metallic glass

► The expansion coefficient α of the Fe-based BMG keeps in a constant. ► The α of the BMG is low, and is close to that of the Kovar alloy. ► The α of the BMG can be tuned by annealing below glass transition temperature. ► The BMG may have a potential for commercial low expansion material.