Magnetic properties of materials
Our laboratory investigates the magnetic properties of the standard and advanced materials used in electrical engineering, of new compounds, and of natural magnetic materials under a broad range of exciting conditions, testing frequencies and temperatures.
Soft magnetics materials are universally used for the generation, conversion and transmission of the electrical energy. They belong to a steadily increasing market, today of the order of € 20 x 109. The INRIM laboratory performs wide-ranging research studies and measurements on all types of soft magnetic materials industrially produced or developed in the laboratory, upon a range of frequencies going from DC to 1 GHz.
The research is focused on characterization and theoretical modelling of magnetization process, ferromagnetic hysteresis and magnetic losses. Besides the traditional characterization under sinusoidal magnetization regime, precise measurements under complex alternating regimes (distorted, trapezoidal, symmetric and asymmetric triangular magnetic induction) as well as under two-dimensional (rotating/elliptical) fluxes are performed.
Flexible measuring systems have been developed, by which one can cover a wide range of induction levels, from J = 1 mT to the saturated state (Js = 2.35 T in the Fe50Co50 alloy). Advanced scalar and vector models of magnetization process and ferromagnetic hysteresis, essential for progress in the material preparation and their energy efficient use,are especially focused on the problems connected with the magnetic energy losses.
In such a context, the INRIM laboratory boasts an outstanding role in the international scientific landscape. The obtained results have immediate technological impact in the field of electromagnetic devices, electrical motor design, particularly in the field of electric and hybrid vehicles, and in transformers.
The technology of magnetic refrigeration around room temperature is based on the exploitation of the magnetocaloric effect (MCE) around the first order magnetic transition of compounds like La(Fe,Si)13 and MnFe(P,Si). INRIM performs experimental as well as theoretical research on the characterization of the MCE and on the relation between materials microstructure and MCE properties. In particular it carries out studies on the temperature and field hysteresis, on the fast avalanche kinetics of the phase transformation and on the slow relaxation effects. The laboratory is equipped by home built Peltier-based calorimeters in magnetic field, heat flux compensation calorimetry and magnetometry.