Table-like magnetocaloric effect due to field-induced inter-cluster interactions in Eu_0.5Sr_0.5MnO₃–EuMnO₃ composites

Abstract

The table-like behavior of the magnetic entropy change is generally observed in rare-earth-based alloys (e.g. La(Fe,Si)13, Gd50Co45Fe5, Gd56Ni15Al27Zr2, Gd ( 1 − x − y ) Co x Al y etc). Here, we report similar table-like behavior in a bulk perovskite Eu0.5Sr0.5MnO3–EuMnO3 composite system with a working temperature span of ∼80 K for a field change of ∼70 kOe. AC susceptibility and time-dependent DC magnetization relaxation measurements confirm the presence of interacting ferromagnetic clusters with a Vogel–Fulcher freezing temperature of T 0 ∼ 42.7 K. The Langevin function fittings of the isothermal magnetization curves show a non-monotonous variation of cluster size with temperature. We propose a model for the high-field dependency of the ferromagnetic cluster coupling in the composite system. This widens the transition temperature region of long-range order formation and hence gives rise to the table-like magnetocaloric effect in Eu0.5Sr0.5MnO3–EuMnO3 composite systems.

Design of Excellent Mechanical Performances and Magnetic Refrigeration via In Situ Forming Dual‐Phase Alloys

“…[ 39–45 ] For instance, metal‐based MCE composites prepared by sintering like LaFe 11.6 Si 1.4 H y /Sn, [ 40 ] LaFe 11 Co 0.8 Si 1.2 /Al, [ 42 ] MnMX/In, [ 43 ] La(Fe,Si) 13 H y /In, [ 44 ] and (Mn,Fe) 2 (P,Si)/Cu, [ 45 ] have demonstrated the potential to achieve better mechanical properties. Otherwise, combining two MCE materials with similar magnetic transition temperatures by sintering has been employed to create a “table‐like” magnetic entropy change, [ 46–49 ] effectively broadening the refrigeration temperature range. Employing phase separation methods can obtain two magnetic entropy peaks in LaFe 11.5 Si 1.5 to expand the temperature range and enhance RC.…”