Magnetic nanoparticles (NPs) are, as the name suggests, a class of nanoparticles made of magnetic elements such as iron, nickel and cobalt and their alloys and chemical compounds. Some remarkable phenomena have been observed in magnetic NPs; the most well-known among them being that of superparamagnetism (SPM) of non-interacting NPs. Superparamagnetic NP’s have found their use in many fields of applied technology including, but not limited to, biomedicine, magnetic resonance imaging, data storage, etc. In an assembly of highly concentrated nanoparticles, the materials’ magnetic properties can be greatly influenced by the dipolar interactions between NPs. It has been found that at sufficiently high concentrations the inter-particle dipolar interactions can produce “collective states” below a system dependent transition temperature Tc. The observed collective states are almost invariably ‘disordered’ and thus called “superspin glasses” as they show many of the phenomenology found in atomic spin glasses. Superspin glass state has been reported in various forms of magnetic NP assemblies; e.g., ferrofluids, dispersions in solid matrices and 3D supracrystals. By further increasing the particle concentration, the existence of dipolar superferromagnetic state is predicted. However, a clear-cut experimental evidence of a dipolar SFM state in real 3D NP assemblies has so far remained elusive. This is most likely due to the stringent geometrical/physical conditions required for inducing a dipolar SFM state; e.g., an ellipsoidal sample shape with NPs on a regular face-centered-cubic (fcc) or body-centered-cubic (bcc) lattice, monodisperse NPs, and the parallel alignment of anisotropy-axis of all NPs. In the project DiSSCo-Hall we will investigate a novel magnetic state of matter; namely, dipolar superferromagnetism (SFM) in 3-dimensional supracrystals made of magnetic nanoparticles. In order to observe the SFM state, highly sensitive, miniaturized magnetometry based on Quantum-Well Hall Sensor (QWHS) technology will be developed. DiSSCo-Hall is a small, interdisciplinary and cross-sector research project that addresses fundamental questions in the field of nanomagnetism, nanochemistry and metrology. Our consortium is composed of 4 partners with complementary expertise working on interconnected areas of: Chemistry, Physics, Theory and Instrumentation. Partner 1-Coordinator: IRAMIS (Institut de Rayonnement Matière de Saclay, Commissariat à l’Energie atomique et aux Energies Alternatives) Partner 2: MONARIS (CNRS UMR 8233 & Université Pierre et Marie Curie) Partner 3: ICMPE (CNRS UMR 7182 & Université Paris Est) Partner 4: ITRON-France What are the chemical and physical limits that render a dipolar SFM state possible? How do they compare to numerical and theoretical predictions? What will be the potential uses of such new magnetic materials? These are some of the questions being addressed in the present project. Simultaneously, the project will offer as its end products, a new class of functional magnetic nanomaterial as well as miniature magnetic field sensing tools, both of which have high potential for industrial applications in numerous fields such as magnetic refrigeration, biotechnology and microelectronics.