Magnetostriction Constants of Nickel-Copper and Nickel-Cobalt Alloys

Abstract

We have determined the magnetostriction constants, λ₁₀₀ and λ₁₁₁, of Ni-Cu and face-centered cubic Ni-Co alloys at room temperature, using single-crystal discs and the strain gauge technique. In Ni-Cu alloys, both the constants are negative irrespective of the composition and their absolute values decrease monotonously with increasing copper content. In face-centered cubic Ni-Co alloys,the concentration dependence is quite different for λ₁₀₀ and λ₁₁₁; λ₁₁₁ is negative irrespective of the composition, showing a flat minimum centered at about 30%Co, while λ₁₀₀ increases almost linearly with increasing cobalt content, passing through zero at about 20%Co, and eventually reaches a large value of 116×10⁻⁶ at 55%Co.