[en] It has been known for many years that the rare-earth intermetallic compound terfenol (Tb_0.3Dy_0.7)Fe₂ is characterized by ''giant magnetostriction,'' which has found practical applications. In this article we report the magnetic properties of a series of molecular beam epitaxially (MBE) grown (110) Tb_1-xDy_xFe₂ alloy films, on sapphire substrates. All the measurements were performed at room temperature with the field applied along an in-plane [1(bar sign)10] axis. However, unlike bulk Tb_1-xDy_xFe₂, it is shown that the coercivity does not fall to zero at the magic ratio of x∼0.7. Instead, the coercivities fall almost on a straight line, with the maximum coercivity for pure TbFe₂ (0.64 T) and the smallest for DyFe₂ (0.22 T). The difference between the bulk and MBE films is attributed to the presence of a magnetoelastic strain term, induced during crystal growth by the sapphire substrate. In practice, the measured coercivities can be described, approximately, with a modified Stoner-Wohlfarth model