Magnetostrictive Alloys with Low Temperature Coefficients of Frequency

Thirty-four magnetic alloys of iron, nickel, chromium, and cobalt were prepared and studied in order to find compositions which have substantially zero temperature coefficient of frequency of longitudinal vibration. Rods of these alloys were made to be used as secondary frequency standards, to stabilize the frequency of magnetostriction oscillators. The same alloys would be valuable for tuning forks. It was found that the temperature coefficient of frequency is a function of composition, heat treatment, temperature, and magnetization. Seven compositions were found which gave temperature coefficients of the order of one cycle in a million per degree centigrade, when properly heat-treated and magnetized. Five of these showed large dynamic magnetostriction, and gave good frequency stabilization when used with a magnetostriction oscillator.