Large reversible magnetocaloric effect in the ferromagnetic pyrochlores R2Mn2O7 (R = Dy, Ho, Yb)

•Magnetocaloric effect of the R2Mn2O7 (R = Dy, Ho, Yb) pyrochlores was evaluated.•Large reversible magnetocaloric effect was observed near TC of R2Mn2O7 pyrochlores.•Their magnetocaloric performances and magnetic properties are discussed. We report the large reversible magnetocaloric effect (MCE) in the cubic pyrochlores R2Mn2O7 (R = Dy, Ho, Yb) near their second-order ferromagnetic (FM) transition at TC ≈ 39 K due to a simultaneous FM ordering of rear-earth R3+ and transition-metal Mn4+ localized moments. Under the magnetic field change of 1 T (7 T), the maximum magnetic entropy change −ΔSMmax is 5.7 (20.1), 4.3 (18.4), 3.9 (13.9) J·kg−1·K−1, and the estimated magnetic refrigerant capacity RC reaches 20.0 (564), 18.4 (503.7), 13.1 (371.4) J·kg−1 for Dy2Mn2O7, Ho2Mn2O7, and Yb2Mn2O7, respectively. We have discussed their magnetic properties and its correlation with MCE in terms of the intrinsic single-ion anisotropy of R3+ ions. Our results demonstrate that R2Mn2O7 cubic pyrochlores constitute a promising material platform for magnetic refrigeration applications in the intermediate temperature range.