Magnetocaloric effect in multiferroic Y-type hexaferrite Ba _0.5Sr_1.5Zn₂(Fe_0.92Al _0.08)₁₂O₂₂

Magnetocaloric effect is investigated in multiferroic Ba _0.5Sr_1.5Zn₂(Fe_0.92Al _0.08)₁₂O₂₂ ceramic with Y-type hexagonal system. Three magnetic transitions, from alternating longitudinal conical to mixed conical at ∼240 K, to ferrimagnetic at ∼297 K, further to paramagnetic at ∼702 K, are unambiguously determined. Furthermore, obvious MCE is shown, and the maximum values of the magnetic entropy change and relative cooling power are evaluated to be 1.53 JKg^-1K^-1 and 280 JKg^-1 for a field change of 7 T, respectively. In addition, inverse MCE is also observed, which might be associated with the first-order magnetic phase transition between two incommensurate longitudinal conical phases.