Fe-system amorphous metal alloy strip having enhanced AC magnetic properties and method for making the same

A high frequency electrical transformer core having enhanced AC cagrientir properties, said high frequency electrical transformer core formed from an amorphous metal strip consisting essentially of a composition mainly composed of Fe, Si, B and C having the formula wherein "a", "b", "c" and "d" are atomic percentages ranging between more than 80 and 82;

• 2 and less than 5;
• 14 and 16;
• and 0.02 and 4;
• respectively, with the proviso that the sum of "a", "b", "c" and "d" is equal to 100, and further containing P, Mn, and S in weight percentages ranging from 0.008 to 0.1, 0.15 to 0.5 and 0.004 to 0.05, respectively, whereby the enhanced magnetic properties of said amorphous metal alloy strip include a core loss in a single cut sheet of not more than 0.12 W/Kg measured at a frequency of 50 Hz and a magnetic flux density of 1.3 T (Tesla).