Variation of Young's Modulus with Magnetization in Single Crystals of Nickel

Young's modulus and its variation with magnetization (ΔE effect) of nickel crystals at room temperature were measured by a 10kc magnetostrictive vibration method. The nickel crystals were a slender cylindrical rod form. A method of growing crystals and measuring procedure with a very small driving field was described in detail. Because E_s, the value of Young's modulus at the saturated state, was the normal Young's modulus, ΔE effect should be expressed as ΔE/E_s, unlike the ordinary expression. The magnetization dependence of the ΔE effect in nickel crystals was observed in a peculiar behavior (two steps, except [111]), similar to those of iron crystals, replacing [100] in iron to [111] in nickel. (ΔE/E_s)_r, the value at the residual point, as a function of the orientation function was on a straight line but for [110]. The elastic constants of nickel were estimated at the saturated state and well coincident with the value at 10Mc. The values were C_<11>=2.53, C_<12>=1.55, C_<44>=1.24, all in units of 10^<12>dyne/cm^2. In the demagnetized state the elastic constants were distributed at random, as expected