TRANSVERSE MAGNETIZATION COMPONENTS IN THE GROUND-STATE OF INVAR GAMMA-NI1-CFEC ALLOYS

To separate magnetic and nuclear scattering and to obtain the quantita tive information concerning the transverse components of magnetization in iron-nickel invar alloys we have undertaken a study of two alloys, Fe67Ni33 and 50Fe50Ni, with neutron polarization analysis at 40 and 3 00 K. The angular dependence of spin-flip and non-spin-flip scattering was measured on the diffractometer D5 of the ILL High Flux reactor. T he main difference which is observed between invar and noninvar alloys concerns the spin-flip scattering, which occurs due to existence of a n average transverse component <(mu)over bar>(perpendicular to) = 0.65 mu(B). This value is well below than <(mu)over bar>(perpendicular to) = 1.15 mu(B), calculated from the model where only HS state for iron atoms takes place (mu(Fe) = 2.8 mu(B)) Thus, the LS iron state should be present inside of magnetic inhomogeneities with R congruent to 10-1 5 Angstrom. Copyright (C) 1996 Published by Elsevier Science Ltd