Magnetism and disorder in palladium-iron alloys

The magnetic and structural properties of palladium‐iron (6.5 at. %) films have been studied using Mossbauer spectroscopy. The films were prepared by the method of dc diode sputtering. It is found that the magnetic and structural properties are interrelated, and depend strongly on the sputtering rate. The degree of disorder in the film increases and the Curie temperature, TC, decreases as the sputtering rate is lowered. The films sputtered at the lowest rate are magnetic only near 4.2 K while those sputtered at the highest rates are magnetic above 80 K. Annealing the films decreases the disorder and results in a higher ferromagnetic transition temperature. The films prepared at the lowest rate show an increase of over 70 K in TC when annealed at 200 C.