Structure, magnetism and magnetocaloric effects in Er₅Si₃B_x (x = 0.3,0.6) compounds

We investigate the structure, magnetic properties, magnetic phase transitions and magnetocaloric effects (MCEs) of Er₅Si₃B_x (x = 0.3, 0.6) compounds. The Er₅Si₃B_x (x = 0.3, 0.6) compounds crystalize in a Mn₅Si₃ type hexagonal structure (space group: P63/cm) and exhibit a successive complicated magnetic phase transition. The extensive magnetic phase transitions contribute to the broad temperature range of MCEs exhibiting in Er₅Si₃B_x (x = 0.3, 0.6) compounds, with maximum magnetic entropy change ($-\Delta S_{\mathrm{M}}^{\max }$) and refrigeration capacity of 10.2 J⋅kg⁻¹⋅K⁻¹, 356.3 J/kg and 11.5 J⋅kg⁻¹⋅K⁻¹, 393.3 J/kg under varying magnetic fields 0–5 T, respectively. Remarkably, the δT_FWHM values (the temperature range corresponding to $\frac{1}{2}\times |-\Delta S_{\mathrm{M}}^{\max }|$) of Er₅Si₃B_x (x = 0.3, 0.6) compounds were up to 41.8 K and 39.6 K, respectively. Thus, the present work provides a potential magnetic refrigeration material with a broad temperature range MCEs for applications in cryogenic magnetic refrigerators.