Interesting magnetic properties of Fe1−x_{1-x}Cox_xSi alloys

Solid solution between nonmagnetic narrow gap semiconductor FeSi and diamagnetic semi-metal CoSi gives rise to interesting metallic alloys with long-range helical magnetic ordering, for a wide range of intermediate concentration. We report various interesting magnetic properties of these alloys, including low temperature re-entrant spin-glass like behaviour and a novel inverted magnetic hysteresis loop. Role of Dzyaloshinski-Moriya interaction in the magnetic response of these non-centrosymmetric alloys is discussed.Comment: 11 pages and 3 figure

DMR study of the magnetic field orientation of the lyotropic-nematic phase of poly (n-hexylisocyanate) solution in toluene-d 8

The alignment of lyotropic-nematic solution of poly (n-hexylisocyanate) in toluene-d8 is observed by deuterium magnetic resonance spectroscopy of the solvent molecules. It is shown for the first time that the lyotropic mesophases of poly (n-alkylisocyanate)s may be oriented by a magnetic field. It is suggested that the symmetry axis of toluene tends to orient parallel to the alkyl side chains. The realignment dynamics of the solution after a sudden change of the field direction is also reported.L'orientation d'une solution lyotrope-nématique du poly (n-hexylisocyanate) dans le toluène-d8 est étudiée par résonance magnétique nucléaire du deutérium des molécules de solvant. Il est démontré, pour la première fois, que la mésophase lyotrope du poly (n-alkylisocyanate) peut être orientée par un champ magnétique. Il est suggéré que l'axe de symétrie du toluène tend à s'orienter parallèlement aux chaînes aliphatiques latérales. La dynamique de réorientation de la solution, après une brusque variation de la direction du champ, est également étudiée