Magnetic Anisotropy and Its Field Dependence as Measured by an Induction Method

A magnetic-induction technique which employs a rotating-sample magnetometer and lock-in amplifier has been used to study anisotropic magnetic behavior at 20°C. When measuring anisotropy constants (K) in ferromagnets, anisotropic spontaneous magnetization (σ) or anisotropic susceptibility (χ⊥−χ∥), outputs vary as K/H, σ and (χ⊥−χ∥) H, respectively; absolute values of K can be determined by measuring the ratio of the second-harmonic component to the fundamental. In Ni, a value of (1/K1)dK1/dH<0.04%/kOe was obtained between 2 and 20 kOe.