We report the current advances of the iMATERIA instrument, i.e, time-of-flight small-angle neutron scattering (SANS), dedicated to observations on the manufactures and energy. The observations with multi-scale(from the minimum q_min = 0.001 Å^-1 to the maximum q = 30 Å^-1), the multi-time domains (> 0.5 sec) and the multi-contrast by dynamical nuclear polarization (DNP) are available. The multi-angle (or stereo) observation of the film specimen bridges the conventional SANS and reflectivity. For the multi-analysis, we developed the real time & simultaneous method by SANS and neutron radiography (NR), targeting the polymer electrolyte fuel cell. As our future plan, we propose to establish the simultaneous triple-analysis of SANS, NR and prompt γ-ray (PG) analysis. By scanning with a beam of 1mm²-size, we map structural parameters determined by SANS and elements determined by PG on the image by NR, as referred to the mapping image.

In recent years, magnetic refrigeration (MR) in cryogenic temperature range has attracted much attention especially for the purpose of hydrogen liquefaction. Most materials used for the MR contain heavy rare earth ions with complex crystal electric field (CEF) energy level scheme. Since energy scales of CEF level scheme of the heavy rare earth ions and system temperature (several tens of kelvin) are comparable to each other, CEF level schemes in zero magnetic field strongly affect the magnetocaloric effect (MCE) when applying magnetic field to MR materials. Here, providing a specific example of the MR material HoB₂, which shows a giant MCE around the hydrogen condensation point 20 K, we discuss the relationship between the MCE and crystal field level scheme, which was determined by the inelastic neutron scattering experiment in HoB₂. We also extend the discussion to general heavy rare earth cases, by using mean-field calculations with crystal field splitting and exchange interactions. The relationship between ΔS_M and crystal field parameters presented here can be useful for developing compounds with a large magnetocaloric effect and advancing the design of magnetic refrigeration materials.