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We report a SANS study of the microphase separation texture of a Pr 0.66 Ca 0.33 MnO 3 crystal as a function of temperature. At T C , ferromagnetic domains display elongated shapes randomly oriented with respect to the crystalline structure, which transform, at lower temperatures, in a texture of randomly oriented and polydisperse 2D sheets of 2 nm average thickness. more...

From the paramagnetic critical neutron scattering of Au0.82Fe0.18 we derive the absolute values of the neutron bulk susceptibility χq=0(T). The excellent agreement between χq=0(T) and the susceptibility, measured with a Faraday balance, validates our analysis, in the frame of the Ornstein-Zernicke formalism, and the resulting enhancement of the critical correlations by the disorder. more...

The results of the first observation of the small-angle polarized neutron scattering (SAPNS) from magnetic flux inhomogeneities in high- T c YBaCuO and LaSrCuO ceramics are reported. The difference between the scattering cross sections for neutrons initially polarized along or opposite to the applied field was found at T T c and in the range of applied field below H c1 of grain in ceramics. The alternative sign effect was observed in remanent field trapped in grains after applying a field. The effect is explained by nuclear-magnetic interference and is proportional to the Fourier transform of the cross-correlator of the magnetic-nuclear (MN) scattering length density fluctuations (SLD). more...