A brilliant cryogenic magnetic coolant: magnetic and magnetocaloric study of ferromagnetically coupled GdF3

Abstract

The use of paramagnetic molecules as cryogenic coolants usually requires relatively large fields to obtain a practical cooling effect. Thus, research into magnetic molecular materials with larger MCEs in fields of ≤2 T is the main focus in this area. In this work, the crystal structure, magnetic susceptibility and isothermal magnetization for the inorganic framework material GdF₃ were measured, and the isothermal entropy change was evaluated up to 9 T. Thanks to the combination of the large isotropic spin of Gd³⁺, the dense structure and weak ferromagnetic interaction, an extremely large −ΔS_m for GdF₃ was observed up to 528 mJ cm⁻³ K⁻¹ for Δμ₀H = 9 T, proving it to be an exceptional cryogenic magnetic coolant.