Energy-efficient and environment-friendly solid-state magnetic refrigeration requires materials with extraordinary magnetocaloric properties. We report the plateau-like magnetocaloric effect activated by tripled magnetic cell in layered intermetallic TbMn_2-xCo_xSi₂ compounds, and the consequent large refrigerant capacity. Substitution of Mn with Co significantly modified the magnetic properties evidenced by two successive ferromagnetic first-order transitions and strong magneto-elasticity as well as significant contraction of the unit cell. Detailed neutron diffraction investigations have established the formation of a tripled magnetic unit cell structure at the temperature range between two magnetic transitions. The overlapping entropy curves near the two transition temperatures results in a plateau-like magnetocaloric effect and enhanced refrigerant capacity. Existence of this special magnetic cell also leads to a variety of interesting physical properties, including a significant drop in resistance and pronounced anomalies in the heat capacity, as well as different responses of the two transition temperatures to an applied magnetic field. The impact of the formation of a tripled magnetic cell on the physical properties is highly unusual for magnetic alloys and merits expanded investigation of this class of magnetic materials to explore for novel applications.

节能环保的固态磁制冷需要具有非凡磁热性能的材料。我们报告了在层状金属间化合物 TbMn _2-x Co _x Si _{2 中}由三重磁电池激活的高原状磁热效应化合物，以及随之而来的大制冷剂容量。用 Co 取代 Mn 显着改变了磁性，这可以通过两个连续的铁磁一级跃迁和强磁弹性以及晶胞的显着收缩来证明。详细的中子衍射研究已经确定在两个磁转变之间的温度范围内形成了三重磁晶胞结构。两个转变温度附近的重叠熵曲线导致类似平台的磁热效应和增强的制冷剂容量。这种特殊磁性电池的存在也导致了各种有趣的物理特性，包括电阻的显着下降和热容量的明显异常，以及两个转变温度对施加的磁场的不同响应。三重磁性单元的形成对磁性合金的物理特性的影响是非常不寻常的，值得扩大对此类磁性材料的研究以探索新的应用。