A new diluted magnetic III-V semiconductor of In1-xMnxAs (x0.18) has been produced by molecular-beam epitaxy. Films grown at 300°C are predominantly ferromagnetic and their properties suggest the presence of MnAs clusters. Films grown 200°C, however, are predominantly paramagnetic, and the lattice constant decreases with increasing Mn composition; both are indicative of the formation of a homogeneous alloy. These films have n-type conductivity and reduced band gaps. © 1989 The American Physical Society.