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 ${\mathrm{(\chi }}_{\perp }{\mathrm{-\chi }}_{\parallel })$ , outputs vary as K/H, σ and ${\mathrm{(\chi }}_{\perp }{\mathrm{-\chi }}_{\parallel }\mathrm{)\hspace{0.17em}H}$ , 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.