Amorphous alloy ribbon, production method therefor, and amorphous alloy ribbon piece

A method of producing an amorphous alloy ribbon, the method comprising the steps of:

• preparing an amorphous alloy ribbon having a composition represented by the following Compositional Formula (A) and consisting of Fe, Si, B, C, and unavoidable impurities;
• increasing a temperature of the amorphous alloy ribbon to a target maximum temperature that is in a range of from 410° C. to 480° C., at an average temperature increase rate of from 50° C./sec to less than 800° C./sec, in a state in which the amorphous alloy ribbon continuously travels in a tensioned state with a tensile stress of from 5 MPa to 100 MPa;
• and
• decreasing a temperature of the thus heated amorphous alloy ribbon from the target maximum temperature to a temperature of a cooling plate for temperature-decreasing, at an average temperature decrease rate of from 120° C./sec to less than 600° C./sec, in a state in which the amorphous alloy ribbon continuously travels in a tensioned state with a tensile stress of from 5 MPa to 100 MPa,
• the increase of temperature in the temperature increasing step and the decrease of a temperature in the temperature decreasing step being performed by allowing the amorphous alloy ribbon to continuously travel in a tensioned state and in a state in which the amorphous alloy ribbon that is continuously traveling contacts a contact surface of a heating plate or the cooling plate,
• wherein the heating plate comprises a first plane on which the amorphous alloy ribbon continuously travels while in contact with the heating plate and wherein only one side of the amorphous alloy ribbon comes into contact with the first plane of the heating plate, thereby heating the amorphous alloy ribbon,
• wherein the amorphous alloy ribbon is vacuum-suctioned onto the first plane of the heating plate through suction holes which are arranged on the heating plate during heating,
• wherein the cooling plate comprises a second plane on which the amorphous alloy ribbon continuously travels while in contact, wherein only one side of the amorphous alloy ribbon comes into contact with the second plane of the cooling plate, thereby cooling the amorphous alloy ribbon, and wherein there is nothing in contact with the other side of the amorphous alloy ribbon during cooling, and
• wherein Compositional Formula (A) has the following formula:
• Fe100-a-bBaSibCc
• wherein a and b each represent an atomic fraction in the composition and satisfy the following respective ranges, and c represents an atomic fraction of C with respect to a total of 100.0 atom % of Fe, Si and B, and satisfies the following range:
• 13.0 atom %≤a≤16.0 atom %,
• 2.5 atom %≤b≤5.0 atom %,
• 0.20 atom %≤c≤0.35 atom %, and
• 79.0 atom %≤(100-a-b)≤83.0 atom %.