On the magnetic anisotropy of chromium

Magnetization and susceptibility measurements have been performed on a single crystal of chromium for field orientations parallel to the symmetry directions [100], [110] and [111] of the cubic unit cell. Particular emphasis is given to the weak temperature-orientation-and field-dependent contributions to the longitudinal (field parallel) susceptibility. For the high-temperature antiferromagnetic phase with transversally polarized spin-density wave (TSDW) the magnetic easy direction is along [100] and the magnetic hard one along [110]. In the low-temperature phase with longitudinal spin density waves (LSDW) the significance of these directions has reversed. The magnetization is not strictly a linear function of the field and shows a weak minimum atB₀1.8 T in the TSDW phase. This minimum does shift discontinuously at the spin-flip transition (T_sf=132 K) to a value of 4.6 T in the LSDW phase. TheJ/B₀-minimum is considered as due to the field induced change from the orientationally degenerated multidomain state into a state with only polarization directions perpendicular to the magnetic field.On leave from Academy of Mining and Metallurgy, Department of Solid State Physics, PL-30-059 Krakow, Poland