Enhanced low-field magnetocaloric effect in Nb and Al co-substituted EuTiO3 compounds

The magnetic ground state switching between antiferromagnetic (AFM) and ferromagnetic (FM) states in EuTiO3 provides the feasibility of regulating its magnetic properties and magnetocaloric effect. First-principles calculations demonstrate that the magnetic ground states for EuTi0.875Nb0.0625Al0.O-0625(3), EuTi0.8125Nb0.125Al0.125O3, and EuTio.75NbunsAlo.125 0 3 are FM coupling. Experimental results also exhibit the FM coupling domination in these compounds, accompanied by a significantly enhanced low magnetic field magnetocaloric effect. The maximum magnetic entropy change of all the samples surpasses 15 J kg(-1) K-1 with a field change of 1 T, which is 1.4 times as large as that of bulk EuTiO3. Especially, the maximum refrigerating capacity for EuTi0.8125Nb0.125Al0.0625O3 compound is evaluated to be 88.1 J kg(-1), more than three times of that of EuTiO3. The remarkable magnetocaloric performances prove Nb and Al co-substituted EuTiO3 compounds to be competitive candidates for magnetic refrigeration in the liquid helium temperature regime. (C) 2022 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology.

Automated summary

The co-substituted EuTiO3 compounds with Nb and Al show excellent magnetocaloric performances, exhibiting large magnetic entropy change and refrigerating capacity, making them competitive candidates for magnetic refrigeration in the liquid helium temperature regime.