Spin-Density-Wave Distributions in Chromium and Chromium Alloys

Two aspects of spin-density-wave ordering in chromium and its alloys are considered. First, hyperfine fields of magnitudes up to 100 kG have been observed to act on 119Sn nuclei incorporated as probes in a 0.4% manganese in chromium alloy. Mössbauer spectra obtained for both commensurate and incommensurate spin-density-wave phases are consistent with the assumption that the magnitude of the hyperfine field is directly proportional to the spin-density-wave magnetization at the nucleus. Second, measurements of the temperature dependence of the elastic properties of chromium have been made in fields up to 150 kG. Neutron-diffraction observations on the effect of magnetic fields and stress on the distribution of spin-density-wave domains in chromium provide a satisfactory basis for discussion of elasticity data. It has been shown that a sufficiently high magnetic field applied to the longitudinally polarized spin-density-wave phase may result in a reversible transition to the transversely polarized spin-density-wave phase. It follows from the results that the spin-flip transition of chromium is of the first kind.