Nanogranular thin films of FexM100-x (M=Au,Ag; x=7,20,39) are an excellent system to study the magnetism of nanoparticles in diamagnetic matrices coupled by direct, RKKY and dipolar interactions. In the low concentration regime we find a super spin glass behaviour, whereas for x around 39 a superferromagnetic state is settled. We have used a bunch of complementary structural techniques (TEM, XRD, HAADF) which show signs for the existence of nanoparticles. These nanoparticles affect clearly the magnetisation and resistivity response measured between 2-300 K. However, the nanoparticle magnetic behaviour can only be defined and interpreted with SANS. For this purpose we ask for the application of a magnetic field using the capability of SANS2D with a H = 2 T magnet to extract the magnetic signal above and below the irreversibility temperature (below 30 K).