Investigating the structure, magnetism, magnetocaloric effects and critical behavior of Eu(Ti,B)O3 perovskites

EuTiO ₃ exhibits various interesting physical properties, including magnetocaloric effect, quantum paraelectricity, magnetoelectricity, and multiferroic properties, thus attracting a broad range of attention from the researchers. The delicate balance between ferromagnetic coupling and antiferromagnetic interactions offers the feasibility of modulating the magnetic properties and magnetocaloric effect for this perovskite. Herein, a range of Eu(Ti,B)O ₃ perovskites were prepared by substituting titanium with different amounts of boron. A comprehensive investigation on their structure, magnetism, magnetocaloric effect, and critical behavior was performed. All the compounds are confirmed to be crystallized in a single cubic perovskite structure with space symmetry of Pm3 m, with the introduced boron uniformly distributed in the compounds. The transition temperatures are determined to be 6.0, 6.5, 5.0, and 5.0 K for EuTi _0.9375B _0.0625O ₃, EuTi _0.875B _0.125O ₃, EuTi _0.8125B _0.1875O ₃, and EuTi _0.75B _0.25O ₃, respectively. The results of both magnetic measurements and critical behavior analysis suggest that appropriate substitution of boron promotes the magnetic transition from AFM to FM in Eu(Ti,B)O ₃. In addition, significantly enhanced low-field magnetocaloric effects were observed in these perovskites. Under field changes of 0–1 and 0–2 T, the values of - Δ S M max are 14.7 and 26.4 J·kg ⁻¹·K ⁻¹ for EuTi _0.8125B _0.1875O ₃, 15.2 and 27.4 J·kg ⁻¹·K ⁻¹ for EuTi _0.75B _0.25O ₃, respectively.