Magnetic properties and large low-field cryogenic magnetocaloric effect in the divalent europium borate Eu2B2O5 compound

We herein investigated the divalent europium borate Eu 2 B 2 O 5 compound regarding its structural, magnetic and magnetocaloric properties by means of experimental determinations and first principal calculations. The Eu 2 B 2 O 5 compound was found to crystallize in a monoclinic structure ( P 2 1 /c space group) and order ferromagnetically at ground state . A large cryogenic reversible MCE was observed in the Eu 2 B 2 O 5 compound around 2.7 K. The maximum values of magnetic entropy change of Eu 2 B 2 O 5 compound reach 13.7, 28.2 and 46.9 J/kgK under the magnetic field changes of 0–1, 0–2, and 0–5 T, respectively. The corresponding values of adiabatic temperature change and refrigerant capacity are obtained to be 3.3, 7.0, and 13.3 K and to be 37.8, 102.5, and 317.3 J/kg. These magnetocaloric parameters, especially under relatively low-field changes, are better than those of the reported candidate materials, which makes the Eu 2 B 2 O 5 compound attractive for cryogenic MR applications.