Properties of Compositionally Modulated Magnetic Films

Compositionally modulated Gd + Co, Fe70Co30 + SiO2, and Fe + SiO2 films by magnetron RF sputtering were prepared, and the composition depth profiles, electrical and magnetic properties measured. The substrate was rotated during film growth, and the rotation rate converted into an equivalent film deposition time T. Compositional modulation of Gd + Co film down to a period of about 120 Å was confirmed. Short times T resulted in amorphous films of uniform composition in the depth direction, while longer T yielded crystalline film with a sinusoidal demodulated composition profile. The Hc of such film was decreased to 1/10, suggesting a means for obtaining soft magnetic properties.