Thin films of the rare‐earth alloys of the Co&sngbnd;Sm system with and without the addition of Cu have been found to have exceptionally high coercive forces. A coercive force of 30 000 Oe was realized with Co3.65Cu1.35Sm films, 4000‐Å thick prepared at a substrate temperature of 500°C using getter sputtering. This technique avoids troublesome oxidation problems usually encountered in preparing films of active materials such as the rare‐earth compounds.