Revealing magnetic correlations in ferromagnetic alloys with polarized SANS

Abstract We search for magnetic correlations at the nanoscale in a ferromagnetic alloy with low critical temperature T c and reduced magnetic moments. We present a small-angle neutron scattering (SANS) study of the binary alloy Ni 0.89 V 0.11 close to the quantum critical point where the ferromagnetic order is destroyed towards a paramagnetic phase by sufficient V concentration. We demonstrate the challenge and the advantage of a fully polarized SANS analysis to discriminate the small magnetic components from the dominant nuclear contributions. We focus on the azimuthal angle dependence of selected cross sections, like pure spin-flip and non spin-flip asymmetry, to finally reveal magnetic contributions at different length scales.