Magneto-optical study of uranium additions to amorphous Tb/sub x/Fe/sub 1-//sub x/

Recent reports of huge magneto-optical Kerr rotations in certain crystalline metallic uranium compounds prompted a study of the magnetic and magneto-optical effects of uranium additions to a rare-earth transition metal amorphous alloy. Using variable composition samples, the polar Kerr effect at a small spot (e.g., 0.5 mm diam) was measured as field, temperature, and composition were varied. Points on the Curie line and the edges of the compensation region were determined from these observations. The compositions studied included (Tb/sub x/Fe/sub 1-//sub x/)/sub 1-//sub y/U/sub y/ with 0.125≤x≤0.550 and y = 0.0, 0.04, 0.07, 0.16. The addition of uranium to Tb/sub x/Fe/sub 1-//sub x/ depresses the T/sub C/ of Tb-rich material much more strongly than that of Tb-poor material. The compensation region does not shift at all with increasing y. It appears that uranium does not contribute to the magnetization of these amorphous alloys, nor does it significantly affect the magneto-optical effects